Ps3 4.88 to 4.89

Ive got ps3 slim on 4.88 cfw,what is easiest way to update to 4.89 cfw without losing my cfw to get back online

or is there a 4.89 bypass to get back online without updating my 4.88 cfw, no laptop/computer so i been using ftp server on my mobile to transfer files to ps3 via multiman