You need a timing light for starters you can buy them from autobarn type shops. Then you need to connect the 2xpower leads to your battery and the third lead goes onto number one HT lead that connects the your spark plug. Number one cylinder is at the front of the engine IE: closest to the front of the car. Make sure you hook this up the right way, there should be an arrow on the connector for the light indicating which way round it should be hooked on. Once its all connected up get a appropriate spanner to loosen the bolts on the CAS just enough so it can e rotated but not so much as it will turn by itself. Next start the engine and point the timing light down onto the crank pulley. There will be a series of marks on the timing cover behind the pulley with numbers on it IE:15BTDC,10BTDC,5BTDC,TDC, etc. There is a corresponding mark on the pulley itself that when you shine the flashing timing light on it, it will point at one of the marks on the timing cover. With the car idling twist the CAS until the mark lines up with 15BTDC. Then tighten up the CAS and recheck it.
Good luck hope i helped
Deren