You've already set 4 threads to the VM. If you want to get more HPS, set 8 threads. And then youll have to set 8 threads in the mining config too. To modify the number of processors for the VM, right click on the VM in the VMware window (after you've shutdown your VM). Then go to settings and set processors to 8. To modify your config file, enter in these commands within the prompt after you've closed the miner:
cd /var/EZSTEEM/steem/programs/steemd/witness_node_data_dir && sudo nano config.ini
Then scroll down via arrow key to a line that says mining-threads = 4
Then change the number from 4 to 8
Press Ctrl + x and then press y
It should be saved now.
To resume mining, enter in this command:
cd /var/EZSTEEM && sudo bash EZSTEEM.sh
Then press option 6
If you want to avoid doing all of that, you can disable Intel Hyper-threading within your BIOS, then run the miner.