There is no installer yet. You can go to SourceForge's "browse cvs" feature and download the files one by one, or you can do it the easy way with a CVS client such as TortoiseCVS
Once you have installed TortoiseCVS (it uses NSIS
) just right click on the folder you wish to download pre-alpha 7 to and choose "CVS Checkout". Fill in the details as they are filled in the screen shot I attached and you will have a directory called NSIS created with the latest CVS version. Right-click it and choose "CVS Udate" to update it to the latest version when it comes.
Pay attention only to the edit boxes in the screen shot. The top list is just a history list, you shouldn't care about it for this.
The top edit box fills up by itself. Just fill all of the edit boxes below it and it should show exactly what's on the screen shot.