So, it's very easy if you actually understand.

I really suck at explaining, so sorry for that...

First you'll have to bind the keys "+lookup" (options > controls > look > look up) and "+right" (options > controls > movement > move right) if you haven't already.
I've set mine to the arrow keys

Launch the mod, press your +right key to choose your "tool" (or how we would call it) , then presss the +lookup button to select the "value" you want to spawn.

You can also toggle noclip/ufo mode by pressing your actionslot 3 button (default is set to 3).
Or if you want, you can change the "dev_ufo_mode" dvar to 1 to use @Lost4468 noclip mode.
To toggle @Lost4468 noclip mode, you have to press +melee to toggle it off/on, then press your smoke grenade button or grenade button to move forward.

When you're done, simply walk over to a location and press the actionslot 1 key (default is set to N) to save the entity.

Now you should open up the games_mp.log which is located in the folder where the mod is.
Now go find the entity you saved, it should look something like this:

Note that I took two different spawnpoints for the purpose of this tutorial.

Now you'll obviously have to remove the time (I do this by pressing ctrl + h, then typing in the time - in this case it's 7:14 - and just press replace all) and then you'll have to change all the * to " (this is also done by ctrl + h)

Also, I'm not sure... but I think you have to remove the comma's and the )'s, but once again... This is simply done by CTRL + H.

Now all you have to do is to put this in your mapname.d3dbsp.ents file.