rsmcmahon

I was getting ready to repair a leaky power steering hose on my 92 400se MB this weekend. After removing the power steering fluid and filter from the inside of reservoir, there are 4 bolts holding reservoir on its bracket. After looking inside of power steering resevior. (Just below the PS filter) I discovered the bolt heads are dom shaped?

Can someone tell me what kind of wrench or socket will fit these bolts?

Thanks,
Russell