You most likely do not need to build this package - it's built automatically by pxt when needed.

Otherwise, instructions follow:

• Install Yotta http://docs.yottabuild.org/#installing
• Install srecord; add it to your path

Run ./run.sh.

You cannot use local version of this package in PXT. After making changes, and making sure everything builds, you need to bump version in git using ./bump.sh and then update version number in pxt-microbit/pxtarget.json.