With what regards do you feel the main trunk is too large to deal with..? That looks like prime firewood to me, block it up and wack it with a splitting maul they'll fly apart then carry them out. What kind of saw are you using, how big is the bar?
I'd personally start with cutting the trunk on this one. It looks like that limb at 45* is hung into the tree by a small dead branch. I think if you first cut the big limb free from the rest of the log you're going to make the problem worse IMO. You want to keep it atached to the rest of the tree and use the trunks momentum to break the top free. It might work it might not but the crotch will be closer to the ground if you cut the trunk first. If that doesnt work then come back with more pictures possibly...
Some times you can get get the top un-hung by getting the trunk to move which would likely happen if you made a cut right behind where you are standing in the first pic. First cut from the top down until the kerf starts to close then pull out and make a cut from the bottom up to meet the top cut. The tree will start to shift so body placement is very important as is being free from pinch points and having a clear escape path. Fortunately for you, it looks like the tree to your right in the first picture is close the top and will stop the log from coming down hill very far when it frees. Expect it to shift while cutting, keep in mind that tree it will keep it from going down hill and you safe.
Above all else, know when to walk away if necessary.
I'd personally start with cutting the trunk on this one. It looks like that limb at 45* is hung into the tree by a small dead branch. I think if you first cut the big limb free from the rest of the log you're going to make the problem worse IMO. You want to keep it atached to the rest of the tree and use the trunks momentum to break the top free. It might work it might not but the crotch will be closer to the ground if you cut the trunk first. If that doesnt work then come back with more pictures possibly...
Some times you can get get the top un-hung by getting the trunk to move which would likely happen if you made a cut right behind where you are standing in the first pic. First cut from the top down until the kerf starts to close then pull out and make a cut from the bottom up to meet the top cut. The tree will start to shift so body placement is very important as is being free from pinch points and having a clear escape path. Fortunately for you, it looks like the tree to your right in the first picture is close the top and will stop the log from coming down hill very far when it frees. Expect it to shift while cutting, keep in mind that tree it will keep it from going down hill and you safe.
Above all else, know when to walk away if necessary.