front door

[Clifford]

how do I prepare a wooden front exterior door for re-staining

[Jeeman]

As Wood stain needs to penetrate the wood itself all coats of Varnish or paint will need to be removed ( I'm assuming its glossed at the moment)

Take the door to a door stripping company who will dip the door in Caustic paint stripper chemicals and your door will come out completely bare and paint free. Or if you like you can hire a heat gun and burn this yourself (though this means loads of sanding if you do) Doing this yourself also means loads of hours.

Once the door is ready apply a high quality Wood stain (cheap stuff is not worth it) wwodstain is normally applied by cloth but now new ones can be applied by brush.

[JohnD]

when you say "restaining" do you mean a further coat of the same product you used last time?

Some times "stain" means a coloured dye that tints the wood (bit like an ink would) that is as thin as water and provides no protective coating; and sometimes it means a low-gloss protective finish, bit like a coloured varnish.

The preparation is quite different depending which you have in mind.