MG Car Repair: Freeze plugs, sheet metal screw, screw driver

Question
My 1965 1098c.c. engine has some coolant seepage coming out of the three plugs on the  distributor side of the engine block. I have bought new plugs but can use some advice on changing them. They are convex in shape and striking them in their centers to expand then equally in limited engine compartment space could be a problem. Are there more water jacket plugs on the 1098 engine block that can not be easily seen that also can leak? Maybe behind the bell housing.
                        Thanks Al

Answer
Hi Albert,
It has been since the mid 70s since I had an 1100 engine out so I don't remember if there is one on the trans end or not. But at the dealership we may have changed the core plugs with the engine in but the tools we had could not be used in the car. We used a slid hammer and a large sheet metal screw after drilling a hole in them. I have seen mechanics use a large screw driver driven through one with a hammer then pried out but even then there is not enough room to work. I prefer to just pull the engine so you can do it right and you have to get the block very clean in the hole before putting in the new ones and it is difficult to drive the new ones in with the engine in the car.
Howard