No worries. WMPF should give you some forms to complete and you will need to get Pensions Bee to do it as well. Pensions Bee will try and claim that you don't need to fill out anything with them but they're full of shit
LGPS pensions work differently to normal pensions. When you say it only had a couple of hundred quid in it - it might be that's your annual pension and the actual value of the pension will be a couple of grand