It's very easy to replace the extendon guards (unscrew and then screw in two bolts - it takes less than 5 minutes), but it would be hard to find new ones since the skates have been discontinued for years now. If you needed to replace them, you could look for a cheap used pair where the guards are in good shape and use those as a donor/parts skate. With that said, I've used a few pairs of Makos (for inline, ice and to officiate) for the past 4 years or so and have never had to replace the tendon guards. I did take a pair of tendon guards off the one pair of roller conversions I retired just so I have the spare parts if needed, but haven't needed to use them.