First, run the package installation script under deps appropriate for your operating system. These scripts require sudo to install packages.
(You can configure your PATH variables by appending deps/bashrc to your ~/.bashrc file, followed by reloading your shell or running source ~/.bashrc.)
Last, run the normal installation calls:
./bootstrap.sh
./configure
make
make install
./configure respects --prefix. A build dependency quirk in UPartsFS means that ./bootstrap.sh also accepts the environment variable $prefix, which should match what you pass to ./configure.
If it looks like The SleuthKit is building twice, it is. That's the UPartsFS quirk. It is not a permanent quirk.