Easy mistake to make fella. I always number my leads (Blobs of tippex,1 on ead 1, 2 blobs on lead 2 etc) and then change one lead at a time and then change the dizzy cap.
Anyhoo Haynes should tell you how to do it but it's quite simple.
Take out spark plug 1 (Nearest the airbox) And stick a chopstick down the hole. Rock the car back forth in 1st gear by pulling on the slam panel until the chopstick reaches the highest point. You've now roughly found Top Dead Centre for Number 1 cyclinder. Pop the dizzy cap off and you should see the rotor arm will be roughly pointing at one of the leads. That lead should be connected to plug number one. You then have a starting point to work out the rest of the leads

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Nick