Latest version 1.0.2: https://github.com/mimblewimble/grin/releases/download/v1.0.2/grin-v1.0.2-498013739-linux-amd64.tgz
Update recommended, unpack in a new directory:
mkdir grin_v102
cd grin_v102
wget "https://github.com/mimblewimble/grin/releases/download/v1.0.2/grin-v1.0.2-498013739-linux-amd64.tgz"
tar zxf "grin-v1.0.2-498013739-linux-amd64.tgz"
./grin