Minimal skill level is required but working at floor level
for prolonged times can be tough on the old knees & back!
The injection equipment is simple to use, but the actual
injection process is so repetitive I've found my mind wanders
every time I've done this I've wound up spraying myself and
the room with the injection fluid stuff. Luckily the fluid
used today is water-based and not as nasty as the stuff used
a few years back.