Problem putting up siding

Much of the siding of my house has been taken off due to replacing many of the wooden panels on the side.

I am trying to put the vinyl siding back up but the trim on the bottom was removed. I am trying to connect all of the vinyl siding back but it is a bit difficult to put back as it doesn't lineup fully with what the siding has to clip into from the bottom and top. Is it suppose to be this difficult or am I doing it wrong? I took picture of it

Attached Images