Then the bolt can be removed from the carrier.

This is as far as I feel is usually necessary for normal cleaning.

Further take-down instructions can be found on AR15.com, an excellent site.

I then spray all parts with a solvent and let them soak while I clean them.

Some parts, like the firing pin can simply be wiped off and they are clean.

Others, like the bolt, must be scrubbed.

I usually find some carbon deposited on the rear of the bolt.

This can be removed with a brass or bronze brush.

If that doesn't work, I use a Very Fine wire wheel to get it clean.