Only 2 ways of doing it.

Try to open a suitable size hose clamp and fit it round the hose and push together and do up again.
Using a socket with ratchet or screwdriver handle prevents stabbing yourself in the hand if you use a screwdriver.

If it doesn't work try making a bit more space by taking things off as the last option is draining, pulling the hose off , fit and refill and purge.
You don't really want to go that last option......

Thanks ktmguy. I changed several of the hose clamps and added one but I still have a leak. I haven't been able to pin point it yet...