This is how I updated the MN wallet on VPS / vultr end:
Logged in to vps
denariusd stop
sudo apt-get install libevent-dev
cd /denarius
git pull
cd src
make -f makefile.unix
sudo mv ~/denarius/src/denariusd /usr/local/bin/denariusd
denariusd --daemon
Then to check correct version running:
denariusd getinfo
Should say "version" : "v3.0.0.0"