This might help: http://www.brothersoft.com/map-editor-9751.html
search Portal gun DIY indymogul on you tube for instructions on how to MAKE your own portal gun
their is no such level.
You send a portal on a ceiling get on the machine with fan jump over you wont make it so then have a portal on floor .:P it is complicated so sry I cannot explain any better.
Once in a while, Valve will have portal be free for a while.
Make a 5x4 Portal going upwards of obsidian.
Pouetpu-games.com level portal
When the boombot bounces back up at you, make a bomb that causes it to go twords the end portal.
It depends on your own experience of Portal 2. Did you enjoy the game? If you did then it is of course, worth playing the very first Portal Installment.
If you have HL2 on PC just go to your steam page and go to library and click on the tools bar and you should see a icon that says Source SDK. SDK is free and able to be downloaded if you own HL2, Ep.2, Ep.1, TF2 or portal. once you download it, you can make, play, and share you levels.
Be a higher level
you have to combine a wirts leg and a tomb of town portal to make the secret cow level bro but u also have to beat the difficluty level like hell nightmare normal
I'm afraid you can only make water portals with the Aether mod. To make an Aether portal with the mod, you make the same structure as a Nether portal, but out of glowstone, and empty a bucket of water into on of the bottom spaces in the portal frame.