How to build terminator I have all 4 parts 10 of each?

If you go inside your base:

1) Look to the LEFT of your base. You should see a statue/robot to the left of the Arms dealer warehouse.

2) Click that statue/robot

3) Scroll down until you see the "Terminator" which looks like a white robot

4) Right under the Terminator picture should be an option to "Activate" if you have all 4 pieces.

5) If the option says that you do not have all the pieces, go back to your "items" inventory and make sure to FUSE your terminator fragments together (10 fragments make 1 whole piece)

Hope this helps!