to start out you need to go to the puase menu then go to options go to keyboard/mouse then go to advanced then enable developer console.

start with sv_cheats 1

noclip: lets the player fly anyware.
thirdperson/firstperson:changes charachter view
ent_create portal wieghd box/ball:spawns a cube/ball
ent_remove:removes an entity in front of you(such as turrets, balls, and cubes)

in any test chamber aim your crosshiar at an observation room then open the developer consle and type the following command [ent_remove] then portal in the observatoin room and pick up a chair and try to bring it back with you then press yuor use item key (E) and you will see that the door is locked.
walk on a button and at the same time jump off keep doing this untill the button stays on.
more soon

test chamber 01 section 1:

complete the puzzle like normal, then, once the dropper drops another cube bring it through the door to the next section.

test chamber 01 section 2:

do the same thing as told above and bring the cube/cubes to the exit.

test chamber 03:

you want to step on the button and at the same time jump off, do this repeatedly until you the energy pelet does'nt explode when you jump off the button, then, complete the puzzle and bring the cube with you to the exit.

test chamber 04:

complete the puzzle and bring the cube with you when it drops.
more soon