If yes, then I would hire an electrician. You need to have a 4 prong dryer outlet to accomodate the dryer's need for a dedicated ground connection, which is why it has one right now (the green wire)
The black and red wires are your two 110 volt "legs", while the white one is the "common" wire. Your Kelvinator is set up to require the dedicated ground, so you either have to supply it through the plug (preferred) or ground it directly to your water pipes behind the dryer (assumes you don't have ANY plastic waterpipe in your house between the washer and ground). Rather than changing the pigtail, pay the $60-80 to have a 4 prong 220v plug installed.