Ok thanks guys, I think I'll read up on the basics and make sure I know what I'm doing, then perhaps start on something more simple.

Don't worry about it man, I'll just start again

I found it differcult to follow your workflow, nice job though

@dave r said:

What do you mean it cannot be reversed? Do you mean modified? Of course it can. You simply open it for editing by right clicking on it and choosing Edit component or double clicking on it with the Select tool.

I don't mean to sound condescending but I think before you tackle this computer case, you should try some simpler things and actually learn to use the program.

Yeah I know how to edit a component, but as soon as your done editing it and click somewhere else the component is saved. is it possible to make a component not a component?

Do you have any good guides I could read or video tutorials?

EDIT: thanks I'll take a look at your workflow

Sigh... see im a massive sketchup noob

Once a component is made can it not be reversed?

FML.... Yeah its working fine for me too now Sometimes I wonder if its got a mind of its own

Are you able to create a void using the highlighted shape selected in the below screenshot? the depth is 5mm.

Thanks for your help.

Right that looks like its worked, its in my OP

Its 20.9MB is that too large?

Ok well am I doing it right by going to edit, upload attachment and then choosing the file, clicking on add file and waiting for it to upload?

Anyone know of any good file hosting websites?

Edited OP and uploaded file. (uploading went to 100% so hopefully has been successful this time)

Sorry guys my internet connection keeps dropping out randomly, I'll try and upload again when my interwebs are working.