There are guys that get seals for them, but it's always seemed a little bit dicey to me... like you really needed to know what you were doing, or have the patience to possibly do it over again. I think it's only possible to replace some of the parts/seals any way... something having to do with a rod not being removable? You can Google it, and find the specifics. It's been awhile since I looked at it.
When mine started leaking, I bought a rebuilt AC Delco unit through Amazon or Rockauto. It's been fine. I saved my original to possibly rebuild/reseal later.
Putting in the new Hydroboost wasn't hard to do. If I recall correctly some of the bolts/nuts were a little difficult clearance-wise, but doable with some patience. I didn't even have to open up the brake hydraulics.
I think the brake switch, had to come out under the dash. There is some sort of fancy clip that needs to be removed. Some people rip it off, and get a new one. I was able to carefully remove it, and then re-use it.
Doing your PS lines at the same time, is probably a good idea, just keep track of where they all go. I re-used my originals, and they lasted a few more years, but I had to replace them all last year. They had been leaking for awhile before I finally got annoyed with it enough to do something about it.
Be ready for something else to leak... my driveway looks like I might step out of the house one day and find a rescue team with Dawn dish soap, ready to clean up baby seals and ducks.
