Most LG phones you open from the back..there is no guide for your phone on ifixit and I can't find anyone posting anything on other sites. Remove battery/battery cover.. there are usually 6 philips head screws securing rear panel to motherboard. Once screws are removed you can use fingernail, spudger or card to ease between rear cover and motherboard. Always go easy to avoid ripping ribbons between motherboard and covers, If the cover won't lift check for hidden screws under stickers or button covers. Don't force anything. Ribbon cables tend to be push on, not slide and lock and most likely you'll have camera/speaker/digitiser/LCD flex ribbons. LCD and digitiser are more than likely stuck to front frame with adhesive that will release with pressure or heat. You'll need to remove all adhesive to get a good finish, also new adhesive for securing screens.

http://www.formymobile.co.uk/lgoptimusdi...

http://www.formymobile.co.uk/km900disass...

These are similar looking to your phone and as most companies don't change things too much they may be able to give you some good ideas on how to get into your phone. Good luck.