I recently did mine, I undid the lower pipe on the n/s rad, mainly because whilst the bike is on the side stand, that pipe looked like the lowest of them all, I drain the coolant out and then replaced it with the Halfords ready mixed pink coolant, I bought 5ltrs for just over £20, I used between 2.5 and 3ltrs iirc.
when I filled the system, I filled it thru the rad, not the expansion bottle (it means taking the front fairings off), I also kept the engine running and removed the top of the expansion bottle, I didn't want to get any air locks, once the coolant in the rad started to bubble and steam I shut the engine off and let it cool down, I then topped it up slightly if need, once again thru the rad. then I put the rad cap and expansion bottle cap back on, run it upto temp again, until the fan kicked in.
job done. I've been on a few rides since and all's well.....
there is every chance I've done something wrong tho, and i'm sure someone will be along to tell me so.....
