[Backdraf7]

Backup ur data-Both with Nandroid and Titanium backup
Backup your Sdcard in case you need the data.
Partition your Sdcard. There are many methods available
Use recovery rom-I believe AmonRa allows this. But since I'm using Clockworkmod, I couldnt use this
Use a Windows partition tool like Partition magic or Paragon
Use a Partitioning LiveCd (Recommended!)-I use Gparted LiveCD
For partitioning, allocate 90% of your sdcard for FAT32, and the rest for ext2 or ext3. I used ext2. I've heard that one shouldnt create an ext partition with >1.5 Gb
Format both partitions
Go back to your recovery roms, wipe data, wipe ext, wipe cache
Install a ROM which utilizes A2SD
Now transfer the data you backed up from your old sdcard to the new one
Optionally restore the data (apps only) from Titanium Backup.

Quelle
hier streetking