If you are ok with taking your '45' apart, then the video is a really good guide;
Search Youtube for; Parker 45 disassembly
If you don't fancy taking it apart, then soaking the lower nib/grip section overnight may be enough.
A small glass jar or cup would be ok, add one or two drops of dish washing up liquid, then add water to be enough to cover the pen section, (2"" deep or so.)
Leave pen in solution overnight, then stand it with nib on a paper towel. This will draw out water plus ink, and after say 30 minutes, give the pen a good shake to get out any water of the socket part where the cartridge plugs in.
You can repeat all this as much as needed, but if you fit a Parker Quink cartridge, you may find it now writes well.
If the ink cartridges are also ten years old, it's worth spending on a few new ones, as ink tends to evaporate over time, even from sealed cartridges.
The Parker 45 is a good design, is very comfortable to hold, and very reliable, given a 'flush' out from time to time.
You can use Parker cartridges, or Parker's ink converters, which then allows you to fill the pen from a bottle, and gives a vast choice of inks to try out, eg. Parker, Waterman, Pelikan, Pilot, Cross, Mont Blanc, Diamine etc.
Edited by Mike 59, 02 September 2014 - 13:47.