Not hard at all its two ways 1. Write them all down n put thrm back one by one 2. Go into cydia and find one of the many apps the backs up jailbroken apps and puts them back after you jailbreak
no seriously either wright down down by going through the cydia manager you can also take screen captures or buy pkgbackup save and then restore.. most major tweaks are now 5.1.1 compatible.