Ok, so I have done quite a few of these and I have had my headaches early on as well. This "can be" a VERY simple install. First off you need a small fine tip. The tip I use is actually a little on the bigger side than I like. The smallest needle tip works best but even then you can still have problems.
The most difficult part of this job is the top two circles, this is because bridging the pads underneath is very easy to do. I have come up w/a very simple easy method.
Take some IDE wire and strip it back an inch or so. Tin the wire and cut it off and then in half. Now go to the board and carefully tin the outer pads. Then add your wire post to the pads. Triple check this step to make damn sure you did NOT bridge the pads. The wire post should be sticking up quite high so as you can just drop the xeno chip over them and they will hold the chip in place nicely.
This next step while extremely easy is very important. Bend the wire over the thicker solder points on the modchip, make sure the wires are nice and close to the pads. Then quickly add a small drop of solder. DO NOT heat that wire long or you risk breaking that nice connection you made on the pcb pad.
Once you have the two circles out of the way, the rest is easy. Just tin the outer pads and each solder point and then fill it in w/solder till you bridge them together. The only thing you have to avoid is bridging both joints together. Take your time because trust me it is not fun removing these chips from the pcb to clean up and start over. Don't forget to cut back your wire post when you are done.
I just did a complete install from start to finish in 30 minutes. That included full disassembly, soldering on the chip, testing it plays burned games, reassembling the unit, and doing a 2nd testing.
Here is a picture of what I just did, so you can see what I mean by the wire post.
While the goal is to perform the mod as quickly as possible, you def. want to take your time and not rush it.
In case you are wondering on the size of the chip.