Trying to replace right headgasket for 2006 mercury mountaineer. removed all the screws but do not know how to remove the timing chain.

Take pictures of everything before you start removing things

Use a sharpe on all timing gears & chains

Look for the marked chain links & note position

Make a drawing of everything

Before you start, buy a book specific to
doing timing chains
A professional book, not a chilton etc.

You will need to replace the chain guides
& clean or replace the tensioners.

Read all you can about what has to be done first

Not a job, even for some professionals