finaly solved ,


Thanku very mach Schturman , your are a genius MAN , fianaly My N9 is back ....

if some one will have same trouble :

via Android to change specific file ( in my case it was .CSS file )

install this : root file manger , or root explorer , or file root

go and browse specific file ....change what u want ( in my case change it to #FFFFFF ) long press on the file and select enable permission .....done ....;save changet file .

roboot ......voila ....; NO BOOT LOOP

thank u very mach