Pull the distributor, remove the cross member and drive shaft. Let the tail shaft of the transmission down as far as you can before the dipstick tube and other stuff start to contact the firewall. You should be able to get your wrenches in there. Be sure you use two wrenches - one for the fitting and the other for the adaptor. Otherwise you are likely to twist the lines. This is more of a problem upon removal than installation but still an important step to prevent
As for tools, I used flare wrenches which you should use for those types of fittings. But even then I had to use a standard open end wrench because the fitting seems to end up in positions where it is impossible to get the flare wrench on. Just be careful with open end wrenches as they'll round off your new fittings in nothing flat. Oh, and you only need to turn them about 1 flat or 60* once the flare makes contact with the adapter. Better too loose than too tight.
Sometimes crows feet wrenches will help, but I usually find standard wrenches work best. The problem with crows feet are when you get your socket extension etc on there isn't room to turn em.