Hope I can give you an accurate answer.
If you have Lingo power supply (a separate box), follow Sc53's instruction. Otherwise, check that your motor pulley has 2 ring, one for 33, and the bigger wheel for 45.
If you don't, then you need to order the 45rpm adapter from Linn. It cost $60 or so, and just snap in, but it is very tight and almost impossible to remove if you change your mind.
www.extremephono.com