Swapping a character while preserving momentum

Hello and thank you for your time.
I recently started my first project. It is a simple platformer where the character can switch between a fast but slippery person, and a slow but stable character at the press of a button. Here is the current blueprint:

This script has numerous problems. The first is that they are separate models, not swapped out each time, and the camera position and velocity are reset each switch. I would appreciate any help.

Just found a lovely tutorial that showed me how to do it! Here it is for anyone else: