This is not that hard a job.
This is what I would do:
-Remove the old seals carefully after noting their locations and positions
-Clean the old adhesive off by using a high quality product such as 3M adhesive remover.
***Be VERY careful if you use other products as they can remove paint as well. I recommend and have had great success with the 3M products***
-Once the locations are clean from the old adhesive and dirt and grime, dry install the new gaskets check for proper general location and specific fit issues. Ideally, use several pieces of masking tape to just hold the gasket in its relative position where, if necessary it can be easily relocated.
***This is done because some section need to be inserted into channels and you want to be completely sure of an even fit all the way around the door perimeter. If you rush this and start gluing and then checking, one often finds too much gasket material in one location and stretched in another leading to wind noise etc etc etc.***
-Use a high quality glue, again I have had great success with 3M, specifically the Interior Trim product (yellow, in a squeeze tube).
-I almost always start at the top corner section of the door and slowly progress across the top. I then do the bottom and then the sides (after being absolutely sure of the overall and specific section fit)
Hope this helps,
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)