Altering an existing font

[Nye Morton]

I work with a music notation program called Sibelius. I've opened their existing proprietary chord font and made a few alterations, but I can't get it to replace the original.

[Erwin Denissen]

Usually all you need is to uninstall the original font, then install the modified version; sometimes a reboot is required.

It is probably best to ask for support from that software vendor.