ok, that tweed material on the doorpanels is frickin impossible to remove, well at least without some sweat and swearing... i took all the vinyl and "tweed" off my door panel and the "tweed" was like 3 times harder to remove than the vinyl, so good luck removing it

you could try redoing it yourself but getting the seem done properly and looking nice is hard to do but possible. you'll need contact cement and a sharp exacto blade to cut the perfect shape with a little extra on the edges to tuck in the gap...
oh ya, i have no idea how you'll do the crazy sharp curve near the door handle, that'll be fun :pface although i've never worked with "tweed" so it might be easier to stretch than vinyl...
if you're gonna recover your seats i suggest you just bring it in to an upolstery place to get it done... they can add new foam, and different padding for extra support, and your seats will feel better than new, you should look into it