rebuilding clutch slave cylinder on MK SD33T

Hi,
my clutch went out all at once, was working fine until then.
I'm trying to get the slave cylinder bolts (14mm) loose, but don't have any tool that can loosen top one.
I just have usual spanner set and socket set.
Hoping someone who has done this can suggest what tool I should buy, so I don't waste money on ones that fail?
Also, a question: the master cylinder fluid reservoir hasn't gone down much if at all, but there is some fluid leaked where the hose attaches to the slave cylinder. In between the two cylinders, there is another thing that is attached to the steel tube from the master cylinder. That tube makes a big circle first. I'm wondering what the purpose of that is, and if it would be why more fluid hasn't leaked out?
Thanks for any help!!