Whats the best and correct way of removing and sticking new ones back on the doors.

if i remember correctly, they are just held on by double sided tape, so you can pry them off with a screw driver (be careful not to break the strips, also put some material over the head of the screw driver so you dont scratch anything)

and just shimmy your way down the strip till its all off.

then youll have to clean all the gunk off, put new tape on the strip, place back on the car.

use a hair dryer heat them up not too hot than grab a edge and peal if off.

or

if you mean the thick rubber that runs around the edge of the door, you will need long nose pliers and you lift out the small plastic clips, then with the new one sit it on line up the clips and push them in.

Thanks guys, I bought a heat gun and they came off easy even the double sided tape was easy to remove..cheers.