How do I unlock a locked phone?

Bought this LG Encore from a cousin a while back, lost it , bought a new phone, found the LG, and eventualy broke the new phone. Now trying to use the Encore but can't remember the pin code I used for the life of me. Is there any way I can reset the pin without opening having one to out in first? Don't have money for a new phone or to even have the broken one fixed, especially since I have a perfectly good one available I just can't remember the pin. Please help me