Leaking power steering box - NEED Help

My power steering box is leaking and it looks like its right around the seal, I would suspect this is common in older car, both my 1971 Dart and 70 Challenger have this issue. How hard is it to fix? Do I need to pull the entire box out? Is there a rebuild kit? any one have a how to do thread I missed?

Thanks
I made a post a few years ago w/ photos. Search for my name.

3 seals, if you count the sector shaft top. All seals can be replaced in-car. The lower seal most commonly leaks. One member said the dealer trick was to blow it out w/ hydraulic pressure (run engine, turn steering to stop), after removing the dust cap and snap ring. You need a Pitmann arm puller and snap ring pliers ($10 & $15 set Harbor Freight), plus a deep socket to hammer the new seal in. Lower seal kit is ~$10 or full kit ~$25 on rockauto. Your Dart has the early small shaft (1972-) and your Challenger has the big shaft box used on all B, E, C and 1973+ A's.

Personally, I would pull the gear-box since removing the steering linkage is the hardest part. Plus, I like to de-gunk, de-rust, and re-paint everything.