I rebuilt my 17 a few yrs ago. You can rap on the jacket with a deadblow and separate the liner. If stuck a press would do it. I would definately do this since its apart anyway. Also there are most likely shims between the block and each jacket. If youre reusing the liners, be sure each liner goes back into its respective jacket and the same jacket goes into each hole using the same shims. If you buy new liners, youll have to go through the measurement process stipulated in the book. Marine Parts
Express has all the schematics and part numbers online. I also bought a lot of my parts
throgh them. Verify all parts needed are available. For example, be sure the injector coppers in the heads are good or available. I think i got the last 3 (MD 17) on the planet but ended up not having to use them.