How to create the HL2 plug puzzle?

[sejievan]

I want to know how to create this kind of puzzles, but unfortunately i can't manage to find any tutorials on how to do it =P could someone give a help plz?

Just for reference... i'm talking about this..

[IMG]http://www.visualwalkthroughs.com/halflife2/episodetwo/ridingshotgun/10.jpg[/IMG]

Thanks since now to everyone willing to help =).

[Rehukotsa]

[QUOTE=Firegod522;49191978][url]http://twhl.info/tutorial.php?id=160[/url]
[url]http://twhl.info/tutorial.php?id=103[/url][/QUOTE]

[sejievan]

Thanks =)