Buy the variator (and 1/2-rings). Take it to your local trustworthy engineering company and ask them to make the removal tool using the new variator as a pattern. A thick flange (3/8 inch) bored in the centre with four attaching holes around the perimeter welded on to an old socket works well. Slip an aerolastic tie-down through the camwheel and tie it back onto something towards the rear of the engine to keep a constant strong pull on the camwheel (and hence cambelt!) when you remove the four attaching allen screws of the camwheel. This way, when you remove the allen screws, you can simply lift the camwheel (with belt still on board) to one side and remove the cam caps to extract the camshaft complete with variator. Then you can clamp the camshaft in a soft-jawed vice and remove the variator with the special tool. Use an accurate torque-wrench for the variator and cam caps and don't forget the correct sealant on the variator threads. Use the proper cam holding caps (www.eldontool.co.uk) and use a dial gauge and adapter to maintain the #1 piston at TDC.
If the cambelt is 'midlife', change it anyway along with tensioner, idler pulley and waterpump, they are all cheap enough to not risk leaving in.
Oh, and don't try to start the engine with the cam-locks still in place.
Buy the cam-locks: if you try to simply phase the cams using pencil marks or whatever, you may run into trouble with the wrong cam timing if the old variator was stuck in an intermediate position when you removed it. Use of the cam locks should prevent that scenario.