Process to get back into mindset of a song you havent worked on in a while?

I have a bunch of songs spanning a few years that I want to rework for a couple new albums I am writing. They have already got such great foundations and interesting ideas, but I am finding it hard getting back into their mindsets.

Any tips or tricks to help me finish these songs? Finding it hard developing them/creating B sections due to being "divorced" from them for such a long time. I want to tune in and get them finished.