Ok guys I did some checking up on this on the net and this site and there are two ways this can go it seems.
option one is topping:
you cut the top off and the next two branches down will start to grow up and become your new main stems.
That seems to be the safest way to go.
The 2nd option is Fim'ing:
what you do is cut about 90% of the main top shoot off.
That part is filled with cells that are splitting in all 4 directions (the directions your branches grow, like a + sign)
This should result in many tops growing out.
Here is an article I found on this site which explains it and has a few pics.
The 1st pic has the guys fingers showing where you would cut if you wanted to top the plant.
the other pics show how to FIM the plant
Good luck guys and please give me feed back on this
These aren't mine, they are Overgrow salvage, as is the preceding article.
One reason to prune is to increase yield or lower plant profile by topping the plants grow tips. The traditional method involves removing the entire growth point but there are now other methods such as the FIM which can dramatically affect the appearance of the plant and perhaps increase yield by increased branch stucture.
From a post by Bud-E
This was originally published as TIP OF THE MONTH "Page 102" in the HighTimes Magazine July 2000 issue.
To increase yeilds and maximize space, many farmers "top" their plants-snip off the top bud. Tradionally, topping your plant causes two shoots to grow back in place on the one pruned off, thus increasing the number of top/main buds. Well thanks to a loyal reader, we've topped that.
This tip came to me by snail mail from South Carolina, With a diagram and a name for this technique. The letter says, "I discovered by accident a pruning technique that all growers should know about". As I read his letter, I remembered that the same thing had happened to me many times and I never took notice. I too occasionally got up to five or six new shoots growing from what I thought was a sloppy topping attempt.
Diagram A shows the tradional method of topping: cutting the whole node off cleanly, to induce the stalk to split into two. But diagram B indicates to make the cut below the center of the node, leaving about 10% intact. This is the key, because the vegetation left behind has cells that are rapidly dividing in many different directions. This can lead to as many as EIGHT tops from a single pruning.
The contributor did not give their name, but requests this be called the "FIM" technique. He also adds, "this pruning technique could revolutionize indoor gardening".