M1Garand Reassembly Issue?

I recently purchased a H&R Service grade M1 Garand for the CMP, it is fully operational, or at least it was. I decided to field strip the weapon to get a better idea of how the gun works, and how it is field stripped. I followed the instructions exactly on how to field strip the weapon. But as I began to reassemble it, I was able to get the trigger housing to fall right in, but when I tried to push over the trigger guard it would go half way and stop, and with a lot of pressure will get 3/4 of the way there, I do not want to break the weapon, but is it neccessary to push do with immense force. Any help will be appreciated.