Now you can cut and paste all your files to your new partition for safe keeping.
In the case that your partition is not large enough, simple open partition magic again and this time select Resize/Move Partitions
simply make the partition larger by increasing the first counter to take space from your first partition, then increasing the middle partition to add the stolen memory to your safe keeping partition.
Reboot and continue transferring files.
Once all your files are out of harms way, it is time to do the clean install.
*NOTE remember the size of the 2 partitions and which is which.. it will be important later.