I recommend NOT modifying anything in the steering system. Fixing what you've got, then putting POWER STEEERING FLUID, NOT ATF, in the system, will result in a very reliable system, by observation. Not many "seals" to replace, in either the pump or the gearbox. There are some internal seals and such in the box itself, buy many are probably plastic-based than rubber-based.
Using Chrysler-spec (the OLD spec) or GM-spec power steering fluid is KEY, here. The old recommendation used to be that it was fine to "top-off" a system with ATF (at that time, either Type A, Suffix A, or Dexron atf), but IF there is a leak, several "top-offs" over time will result in too much non-compatible fluid in the system. If it has a reddish tint to it, it'll seep past the seals which are not totally compatible with atf, but flushing the system will fix that, usually, from my own experience. I'm not sure what spec-psf Chrysler is currently using. The old GM psf worked great for me. Originally USA-GM PN 1050017, but now probably in ACDelco bottles as 89021182 (qt).
As for "changes", the lower part of the steering column is different. There are conversion items to go from manual steering to power steering, but I don't know of any to do the reverse of that.
ONE of the things I like about Chrysler products is the directness of the power steering response and the generally faster ratio of it when compared to GM or Ford. Going to a manual system will result in about 5 turns lock to lock, rather than the current 3.5. No matter how much you don't drive it, that's what you'll end up with all the time. More effort, slower steering ratio. To me, that's not a good trade-off.
CBODY67
Fix what you've got, it'll be much easier and quicker.