First off, I can't Believe Anyone Didn't post a Comment about the K & N Filter,
You do NOT have to REPLACE it, K & Ns are LIFETIME Filters, all you do is
"RECHARGE" it( REmove, Clean, Dry & Put Oil coating on it, then Put back in) Any Motorcycle shop/Dealer has the "RECHARGE" KIT!!!! I Think around $12 to $18, or so!! 2nd, the Tank removal should be done with (2) people, but CAN be done solo, the other posts give the basic explanation, I've done it already a couple-o-times, with the help of a friend. I did NOT take it all the way off either, just lifted, put a brace to hold it up, then worked under it, about 6 to 8 screws holding the air box cover on! there is a SHOP Manual online that Can be purchased for Under $9.00, I'll try and send the Linkn you can download the entire manual, find the page(s) ya need, print em out, go work on your CBR, Easy!! As soon as I find the Info I'll post to ya, Good luck!