How hard is it to replace the weather stripping between to top and the windows?

Do they just slip out? The front seems to have 2 bolts but is there adhesive in play as well?

Any thoughts on used vs new? These seem to be very pricey, so I don't want to order them to find out its a massive undertaking.

Thanks!
dsd

 

I just did the one on my passenger window. Unscrewed the fasteners and pulls right out. When iinstallng press one side in the compress the opposite and slid over the metal lip until it locks,then install the screws. No adhesive at all.
BobRoy actually found one for me in a wrecking yard for $15.00. It fit perfectly, mine had a piece torn out of it.