I have a laptop running Ubuntu 11.10. I've replaced the HDD with a 120GB SSD, and to save some precious disk space I utilized one of Steve Hanov's tips for optimizing Ubuntu to run on a USB key or SD card; specifically, I implemented his third tip, and compressed
/usr to a squashfs read-only volume mounted with a normal rw volume using unionfs.
Now, I've installed another space-heavy program, and I'd like to repeat the procedure. However, I don't know how to... I can't inflate the squashfs volume to get to square one and do the same thing again, simply because there's not enough space on my drive left for that.
How do I go from where I am now to (approximately) where I would be if I had applied the space-saving tip the first time today?