My problem is with unwanted light spots outside of the picture frame

Anything apparently from the bottom of the lens would usually indicate a foreign object in the space behind the lens - possibly a bit of broken bulb or reflector or an insect etc. Also possible is damage to the lens itself on the inside, damage to the bulb or the bulb reflector surface (probably up near the top rear). If you can turn the projector upside down or on it's side then shake it gently and see if the spots move - you may be able to shake the object free. you should be able to pull or turn the focus ring/zoom lens assembly until it comes free (but dont force it - I am not certain how to open but this should be obvious) to clear anything there. here is the dell site http://support.dell.com/support/edocs/acc/2300MP/en/trouble.htm and here is how to check the bulb etc. http://support.dell.com/support/edocs/acc/2300MP/en/install.htm#4 Hope this helps :)