Sec. Partition not added

After init. the mod. firm 1.1.2.8 (thx@progger) and after 2 day of config i succeed to use the wlan hdd as ethernet bridge, because after flashing the official 1.2.3.9 all my setting are lost and it was not possible to reconfigure the wlanhdd as a ethernet bridge. so i installed the moded firm but if forgot to format the second partition from the hdd. My device has a 60gb and on the first /part1 (40gb) are all of the needed files.
How do i create the second /part2 hdd with the 18gb left without deleting everything. i now it must be a linux order but in this espacialy case i like to ask before breaking any more

thx

best regards

Zatanas