Hey everyone I haven't been on this forum in a very long time so please excuse me if this has been discussed before. However, I cannot find a clear explanation on whether or not it is possible to reset a legendary skill after it has already been reset once. Is it possible to, for example, get 100 Sneak then reset it to Legendary Sneak, then reset it again for a second time?

Yes, you can reset it as many times you want as long as its reached 100.

You're awesome. Thanks!

You have no choice but to reset over and over again if you want to take every single perk in all the trees (that's something like 253 perks). The only question is what happens if you keep build up the maximum number of perks without allocating any of them and then get one more perk (by resetting and leveling). The UESP says you might loose all the unused perks but that's unverified. Seems kind of weird to build up that many unallocated perks....