Remodeled a room that has 12 can lights and had 4 switches all around the room. How to wire 2 sets of lights together and connect to switch when the power source is not located.

If you have 4 switches, two of those switches will be 3-way switches and two will be 4-way switches. You can remove the two 4-way switches, connecting like colored wires together and put blank cover on the box. You cannot hid the box in the wall.