I have two young maple trees on my property. The trees were not cared for by the previous owner so now I am stuck with two trees that do not have a "central leader". I realize it is too late to correct that, I also realize I need to remove the mulch away from the runk and expose the root flare. What I don't know is what lower branches on the trees need to be pruned off so as to help train the tree take on a proper healthy structure as it matures. Problem is I don't know how to determine what limbs need to be cut off and I can't really afford to pay a professional to come in to do the job. Like I said above, I know it is too late to establish a central leader, but in light of that, what branches should I prune off these two trees? Can somebody give some advice to a newbie? Below are some pictures of the two trees in question. Any help would be greatly apprecaited! :)

Thanks!

Tree #1

Tree #1 Close-up

Tree #2

Tree #2 Close-up