Hi Swegmang, sorry no in MoI it's not easy to change a fillet after you've created it. If you think you're going to want to change it later it can be a good idea to save off an unfilleted version to a separate file so later on you can load that file back in and do a different fillet. Some other CAD programs like SolidWorks, Solid Edge, etc... can change fillets because of how they keep the history of operations. If changing fillets is a big issue for you some other program that has that type of history modification might work better for you than MoI.

Thanks for posting your file - I'm not quite sure what area in the file you're trying to fillet though.

- Michael