First, download musl libc source package from its download page: http://www.musl-libc.org/download.html . Here we use 1.1.5 as the example.
After unpacking the source package, configure and build it by
$ ./configure $ make
Then, install it by
# make install
Note that musl libc is installed into /usr/local/musl and you need to add
$PATH so that you can invoke