Note: Original game needed to play! On Steam or elsewhere, on sale often for $1.49 https://store.steampowered.com/app/70/HalfLife/).

Setup Sidequest and Dev mode first! Instructions: https://sidequestvr.com/my-app/124

Click "Download (Sideload)" to install the port!

Start lambda1vr once on your headset until it shows the menu screen. At this point exit the app! You will find that a "xash" folder has been created on your headset.

Locate the install of half-life on your PC, if installed from Steam then it will be somewhere like C:/Program Files (x86)/Steam/steamApps/common/HalfLife/

From your PC, copy the whole "valve" folder to the newly created "xash" folder on your headset (This will take up to 10 minutes). Copy the whole folder - you can just drag and drop it into "xash". Allow to overwrite if asked.

Using the Sidequest explorer to copy over the files is most fail-prove.

Go to "Uknown Sources" in your headset and start Lambda1VR.