The decisions an Attorney can make on your behalf depends on the type of Lasting Power of Attorney (or LPA) that has been set up.
There are two types of Lasting Powers of Attorney (or LPAs):
1. Property & Affairs – this allows the attorney to deal with your property and finance as you specify, even before capacity is lost;
2. Health and Personal Welfare – this allows the attorney to make decisions on your health and welfare only when you lack the mental capacity to do so yourself.
You can choose to prepare just one or both types.
Further reading:
OPG Campaign Praises Benefits of Lasting Power of Attorney
Choosing The Right Person be Your Power of Attorney
What Is The Difference Between a Lasting Power of Attorney And a Deputy?
gov.uk – Lasting Power of Attorney: Acting as an Attorney

You need to decide who your Attorney will be (you can have more than one). Next, you will need to complete the forms required for their appointment and register your LPA with the Office of the Public Guardian (this can take up to 10 weeks).
Further reading:
OPG Campaign Praises Benefits of Lasting Power of Attorney
Choosing The Right Person be Your Power of Attorney
gov.uk – Make, Register or End a Lasting Power of Attorney

The registered LPA does not have to be certified by a solicitor. If the donor has mental capacity, he or she can certify the document themselves.
Further reading:
gov.uk – Make, Register or End a Lasting Power of Attorney

You can complete an OPG100 form find out if someone has a lasting power of attorney (LPA), an enduring power of attorney (EPA) or a court-appointed deputy acting on their behalf.
Further reading:
gov.uk – Find Out If Someone Has a Registered Attorney or Deputy

You will need to check the terms of your current LPA and if you don’t have any replacement Attorneys, or you want to change the way your Attorneys act, you will need to make a new LPA.
Further reading:
gov.uk – Lasting Power of Attorney: Acting as an Attorney

Your Attorney(s) do not have to be paid. However, you may decide you would like to recompense them as the role carries significant responsibility. If you have chosen more than one Attorney, you may like to pay them differently. It’s not uncommon for Attorneys to claim out of pocket expenses when acting on your behalf.
Further reading:
gov.uk – Lasting Power of Attorney: Acting as an Attorney

An Attorney can resign at any point for any reason. You will need to complete form LPA005, send it to the Donor and a copy to the Office of the Public Guardian (or OPG) and any other Attorney involved.
Further reading:
gov.uk – Lasting Power of Attorney: Acting as an Attorney

It’s not possible to add an Attorney to a Lasting Power of Attorney once it’s been registered with the Office of the Public Guardian. It’s better to revoke the current LPA and make a new one.
Further reading:
gov.uk – Use or Cancel an Enduring Power of Attorney

You can ask the OPG to stop the registration through an objection. Certain rules apply:
– If the Attorney is bankrupt or interim bankrupt (this only applies to the property and financial affairs LPA);
– The attorney is a trust corporation and is wound-up or dissolved (once again this only applies to the property and financial affairs LPA)
– The attorney dies.
Further reading:
gov.uk – Object to The Registration of a Power of Attorney

If you’re married or in a civil partnership, it’s a common misconception that your spouse will automatically be able to deal with your affairs and make decisions about your health and care on your behalf. However, this is not the case.
If you lose the capacity to make your own decisions and you don’t have a valid lasting power of attorney or enduring power of attorney, you will need to apply to the Court of Protection.
Further reading:
OPG Campaign Praises Benefits of Lasting Power of Attorney
What is the Difference Between a Lasting Power of Attorney And a Deputy?

You will need to register the death. In England and Wales there’s a time limit of 5 days. In order to register the death, you will need:
1. A medical certificate; or
2. Permission from the coroner that you can register the death.
The funeral director will need a copy of the ‘certificate for burial’. Otherwise, you will need to complete an application for the crematorium.
Further reading:
My Father Left a Will – Do I Need to Apply For Probate?
gov.uk – Register The Death

This process can take a long time but in normal circumstance the grant of probate (or letters of administration) usually takes between 2-3 months.
Further reading:
Probate Fee Increase Scrapped by Government
gov.uk – Applying For Probate

If an Executor doesn’t follow the terms of the Will, you should immediately contact them to let them know your concerns. If you are not satisfied with the response, you can make an application to court to remove them.
Further reading:
5 Key Benefits of Appointing A Professional Will Executor
What Happens if I Want to Dispute a Will?