How much space have you got for it to fall in any direction? as that will define how high up the trunk you will have to cut it?
Accurately getting it to fall in a particular direction is very straight forward. Rope the tree above where you are going to cut it. Tie the tensioned rope a concrete fence post or something non-movable like this, if it is not safe to have someone pulling on the rope. Cut a horizontal V in the direction of the fall about half way through the trunk and then cut through Horizontally on the other side about 1/2 way through the trunk about 25mm ABOVE the V. Put a metal wedge into the horizontal cut and hit with a hammer, this will start the tree falling. Obviously you need to be behind the tree, so it does not fall on you!
When cutting wood with a chainsaw it is important that the gap does not close as this can cause the saw to kick back. If you hire a chainsaw, make sure you have the proper gloves and ideally trousers. These both contain thin stands on nylon material which clogs the saw and stops it before you have taken your hand or a limb off. A chain saw can cut through a branch in seconds, it will go through a limb even faster!

I was fortunate in that a friend of mine used to be a woodsman at Longleat and taught me how to use a chainsaw before I bought one for myself.