This piece of equipment was bought from the this pledge.
When using the auto de-soldering pump please clean it BEFORE use, making sure it's cool enough to do so.
To release the filter barrel, pull down the latch at the back of the gun, similar to how you'd cock a pistol.
The barrel needs to be pulled towards the back of the gun and should come out with little force. Be very careful NOT to snap the plastic bit at the front!
If there is debris blocking the conical part of the spring, use the heat gun and melt the solder away, it should come out easily.
Filter emptying video: http://www.youtube.com/watch?v=dezW2QqewLE
Spare filters and tips were taped to the side of the machine,
but don't seem to be around anymore (see below)
They are in one of the electronics drawers.
Looked like it hadn't been cleaned in quite some time. The filter was unrecognisable and the tip was pretty battered. I gave it a clean out, replaced the filter and switched out the tip.
This is where the spares live: