Before I get into this, I want to thank Michael-GnL-Michael for starting the thread that prompted Craig to ressurect Dean Coy's TASA and Gabe Dellevingne's LegASAT from the old GbL Gallery. I was considering going the 2HB route (using Fralin P-92s), but you guys unknowingly convinced me to keep it G&L or real or something like that.

Intro
I've been a G&L owner since the mid-90s; my USA S-500 was my first electric and is still my baby. Through the years, I've become increasingly interested in tinkering with my gear, but I could never bring myself to risk screwing up my S-500, so I decided to purchase project guitar I would feel comfortable working on. I'm a fan of the dual fulcrum vibrato and the S-500/Legacy body style, so a Tribute Legacy seemed like a pretty good fit. In the end, I bought a used Tribute Legacy HB, because it would give me a chance to try G&L's AlNiCo single coil pickups, as well as a humbucker (at this point I was still thinking about trying a 2HB setup).

After playing the Legacy HB through various amps (a 1974 Fender Vibrolux Reverb, a 1978 Fender Champ, and a 1981/82 Fender Deluxe II) for a few weeks, I realized three things: (1) I don't think I'm a humbucker person, (2) none of the pickups on the Legacy HB cut like the MFDs on my S-500, when playing with a drummer, and (3) I've been completely spoiled by the Sperzel locking tuners on my S-500. Before addressing the first two issues, I decided to replace the existing (Ping?) tuners.
Installing Hipshot Grip-Lock Locking Tuners
At first, I was just going to buy another set of Sperzel's, but I was able to get a pretty good deal on a set of Hipshot Grip-Lock Locking Tuners, and I thought it would be fun to try something new. Most of the reviews I've read on Hipshot's tuners have been glowing, and the folks at Hipshot were very helpful when I called to ask them questions. Hipshot's Grip-Locks aren't a drop-in replacment for the stock Tribute Legacy HB tuners, but, then again, I don't think drop-in, locking tuner replacements exist for the Tribute series.
When the tuners arrived, I removed my old tuners and installed the new, screwing the nut onto the post tight enough to hold them in place, but loose enough for me to adjust them (I decided to use the stock washers because the Hipshots were a little smaller and exposed a bit of the wood that the stock washers had roughed up). I used my handy StewMac straight edge to line up the tuners, and then marked the screw holes with a pencil. The Hipshot tech I spoke to recommended using either a 1/16" or 5/64" drill bit, so I started with a 1/16" bit, measured the depth I needed, and then marked the depth on the bit using a strip of masking tape. Then I removed the loosely attached tuners and carefully drilled the holes.
The holes looked pretty good, but I couldn't get the screws to go in, so I switched to the 5/64" bit. Once the holes were widened, I tried putting another screw in, but I still had to use so much force that I stripped the head a bit. At this point I decided to consult the Interwebs and found a few tuner installation threads that recommended screw lubrication. I didn't have any beeswax available, so I just rubbed my screws against an old candle and they went right in.
Here's a shot of the completed installation:

I haven't had a chance to restring the guitar and test them, but they look pretty nice. I'll report back once I've had a chance to try them out. Oh, I called Hipshot to ask if I could buy some replacement tuner screws, and they offered to send me a set for free. I know screws are cheap, but it's still pretty cool.
Next Up: Ordering a New Pickguard from Chandler Guitars