Convert EXT4 to EXT3 (resolved)

[The_Dadu]

My initial research has not been successful, so now to the experts!
I have an external 1TB USB2.0 drive formatted as a single partition EXT4 drive. It has worked fine for a long time and has not caused any problems. But, I recently purchased a PogoPlug (a small network server that uses an user-provided USB drive). The Pogo works fine with all my other FAT32, NTFS, and EXT2/3 drives. But, the PogoPlug does not support EXT4 (vendor refuses to provide a solution). I don't currently have a sufficiently large other drive to copy the EXT4 drive to save its contents and reformat the EXT4 to EXT3.
Does anyone have a suggestion to converting a EXT4 drive to EXT3 without losing the contents?

[Just17]

A bit long winded but ..........  reduce the size of the partition as much as possible .........  in the empty space create an ext3 partition .......  copy data from first partition to second ....... 

if all data won't fit then reduce the ext4 some more, expand ext3, copy more data ....... etc etc

[thorper]

If you have any old drives laying around then you could buy a caddy and use your old drives as temp storage. Copy ext4 drive data to temp storage drive, reformat ext4 to ext3 then copy back data. I always keep old drives when I do upgrades or if disposing of worn out machines.

[The_Dadu]

Thanks to both of you for your responses. I was afraid the answer was going to be along those lines. I've ordered a new external formatted for MS OSes to use with the pogoplug and will keep the 1TB drive in its current place for now. I actually have multiple old drives in caddies, but none of them are large enough to keep the copy/reformat/copy back reasonably manageable.
I appreciate your help.

[The Chief]

Don't know how tight you are on finances, but this may help (and you can probably beat this by some careful searching).

http://www.amazon.com/Toshiba-Canvio-Basics-Portable-Drive/dp/B005J7YBRW/ref=sr_1_2?s=pc&ie=UTF8&qid=1363546192&sr=1-2