I bought my wife a 125LE 2 weeks ago and she's really taken to it. In fact I liked it so much I bought an xt225 last week. We're both quite happy with the bikes, but fairly new at this.
Anyways, seeing the clear recommendation on these forums was getting the chain guide and frame cradle, I ordered those and they appeared last night.
Chain guide was fairly easy. I'm not positive it's perfectly aligned yet, we'll see soon enough.
But this frame cradle -- phew. I looked at the posts here before trying, so I knew it wouldn't be easy. I finally installed it and I think I can lend some advice to the next person to try.
For my install:
You'll need -- 10,12,13,14 metric sockets and equivalent wrenches and a nut driver (screwdrivers/punches perhaps also)
1) loosen the exhaust enough so that it comes out of the engine. remove 2 bolts in front, one on the left of the bike and one on the back. You don't have to take the exhaust completely off, it seemed to stay in place, but you can then slide it forward enough to have clearance to fit the front of the frame cradle in. My cradle fit w/ 2mm clearance from the stock exhaust. I hope that's enough.
2) remove the 3 bolts holding that black plastic guard and take that off
3) remove the 3 bolts through the frame (the ones you'll be replacing with the 3 that came with the cradle) -- the bottom one (left's call it A) and the two front ones (B - lower and C - the upper).
4) Wedge the frame cradle into place, under the exhaust.
5) BBR tech guy said since my bike had been ridden, the frame probably bent already, hence the common misalignment problem. Mine was off by about 2-3mm. So I suppose if you haven't ridden the bike, and that's true, you should just be able to stick the back bolt through, then attach the front two and tighten it up. (Lucky you.)
6) Originally I tried starting with the back bolts first - no go - and then front first - no luck, and it still was too misaligned to pry into position. What eventually worked was: Insert the upper C bolt in, just a short ways, so there was some play in the joint. Less than halfway through - maybe about 1 cm inside the front tube. Then insert the bottom A bolt in, to the point of misalignment, get out the nut driver (13mm) and thread it in, using reasonable pressure pushing on the bolt. Once it screwed through the first side of the frame it slid through and over to the back side.
7) Then I stuck in the B bolt and got both the B and C bolts all the way through both sides of the frame.
8) With the nut driver again on the A bolt I couldn't get it through the back side, because the depth of the 13mm socket was too deep to allow me to put pressure on the end of the bolt. So I placed a smaller nut I had lying around inside the socket, and it threaded in like a charm with the pressure I could then apply.
9) Then it was pretty much just tightening all the bolts down and reattaching and tightening the exhaust. I didn't use a torque wrench -- so I probably should get one and make sure I've got them on snugly enough.
10) Understanding that some frames may be bent more than others -- this may not be universal advice. The BBR guy on the phone told me to: Start with the bottom A bolt, then using a screwdriver or punch in the B location pry the thing until the C bolt went in. If you can't do that, or to facilitate more play, loosen - but don't remove - the other engine mount bolts. There were two more on the front, one on the back directly above the A bolt, and one on the top. (He said I'd have to take the tank off to get the top one on the head. I didn't try this, since my method worked, and that sounded like too much work.)
I hope this is sound advice and may save the next guy some frustration. I'd be happy to hear any feedback, tweaks or better suggestions.