4.1. Extensions, updates

According to your aims you may need additonal stuff: build files of new projects, host environment, toolchain. All that stuff, distributed along with any, has plain archives format and is installed by plain unpacking into root of working directory:

tar xzf additional-pack.tgz
The stuff update goes with similar unpacking, unless instructions with new archives do not say something different.

Files from other sources and vendors may require other steps for installation. For example, archive files are located in nested directory, named after the archive. In that case it is needed to move them to the root of working directory:

tar xzf new-toolchain.tgz
mv new-toolchain/* .
rmdir new-toolchain