528T how to on then off?

Hi and thanks ahead of time for your help! I have a car which does not have a remote trunk release and have installed a remote lock/unlock unit which has ability to trigger trunk release. What I have so far is a linear actuator which pulls the cable which pulls the cable which releases the trunk latch. What I need to know is how to wire up my two 528T units so they do the following after pressing the trunk unlock button on the remote. 1. 528T receives signal from the remote control unit which causes the 528T to sends positive power to the linear actuator for 10 seconds and then cuts power 2. After 15 seconds the second 528T reverses the voltage to the linear actuator to extend it back. Make sense? In other words: Press trunk button: Linear actuator withdraws the cylinder, after 10 seconds it stops getting power. Then, since trunk latch has been released and need the linear actuator to extend so when shut trunk it will latch, the second 528t reverses the polarity of power wires to the linear actuator so it extends. THANKS! I am pretty adept at most things electrical, wiring up, soldering but for some reason my brain has trouble understanding relays.. :P

anyone?

Looking over some other posts I should have mentioned that the linear actuator has a built in clutch/limit switch so in reality it does not matter if power is on to it initially for 10 or 90 seconds. Just need so say 10 seconds after it is actuated by the remote that however this gets wired up it reverses polarity and thus extends the actuator back out.