You could install it alongside Bitcoin Core. Once it has synced you can pass user/password and it will use your bitcoind instead of remote blocks. Read the README, it's all there:
add-apt-repository ppa:lightningnetwork/ppa apt update apt install lightningd mkdir -p ~/.lightning/plugins echo 'disable-plugin=bcli' >> .lightning/config cd ~/.lightning/plugins wget https://github.com/nbd-wtf/trustedcoin/releases/download/v0.6.1/trustedcoin-v0.6.1-linux-amd64.tar.gz tar -xvf trustedcoin-v0.6.1-linux-amd64.tar.gz cd lightningd