I have replaced every part on these mantles myself. You are better off replacing the entire magnetic stirring assembly than trying to replace the magnetic disc itself. Then you can be sure the entire assembly is going to function properly. If you replace just the magnet and you can’t achieve the RPMs you wish to achieve then you’ll have to take it apart again…and that’s always lame. You can hit up Ychem and order some magnetic stir assemblies for super cheap…I think they’re like $5 each. I bought a half dozen PIDs, 4-pin Aviation connectors for the thermo-probes, heat-sinks, Magnetic Stirring Assemblies plus a couple dozen discrete semiconductors (TRIACs) to be prepared for repairs…because they will be necessary. If you have trouble sourcing the components or have questions in general I’d be happy to assist.