Recently replaced all coolant hoses. I used channel lock pliers. You will need ones small enough to fit up there. It isn't easy and might be easier to use worm clamps to replace the factory ones when you install the new hose.. You can also purchase the pliers I'll link to you below but they really can't get into all the tight spots. IIRC they did help out with the lower hose.
http://www.thetoolwarehouse.net/shop/AP-9409.html 
