This is the method I use:
Run the engine from cold with the cap off and rev it to 2k now and again. While you are doing this squeeze all the pipes you can get your hands on, and keep the coolant level topped up. It will eventually start to boil over, at this point turn the engine off. Once its settled down top it up to the max mark and you should be good to go!
Even then sometimes the only way to get rid of persistant airlocks is to give it a good thrash

No need to switch the heaters to hot on a MK2 as the coolant is always flowing round the matrix regardless. Its good practice to do it anyway, especially if you arn't sure if coolant flow is blocked by the heater controls or not. The MK1 needs the heaters setting to hot
