[akstrohm]

Try to be patient. It's very common to have pigs that are reluctant to try new foods. Here are a few things you can try:

-Feed only a few new foods at a time. Start with bell peppers and other vegetables.
-Try feeding favorite foods opposite of new foods. So if you give him lettuce in the morning, give him peppers at night.
-Cut the vegetables differently (strips, chunks, etc). Cut open foods like tomatoes or grapes so your pig can see what's inside and get to it easily.
-Get another guinea pig if you don't already have one. Not only is it better for your pig to have a friend, but watching another pig eat new foods may encourage yours to do the same.
-As mentioned above, leave the food in the cage for several hours or until it gets wilted/dirty.

Don't cut back on the hay or lettuce. He needs these. And I wouldn't worry too much about him not eating too many pellets. Hope this helps!