Rebuilding motorcycle after timing chain skip 62K Km

Getting warmer, spring is coming. I think there is a way to separate the cylinder block from crankcase by removing gudgeon pins ang lift the block with the pistons inside while leaving conrods connected. I don’t have to crack the crankcase open but just level the cylinders and lift the blocks until the pins become visible through scallops. I need new circlips and a tool to remove them. Anybody disconnected the pistons to tell how stiff the circlips are? I need to work in a tight space at 90 degrees with the pistons half exposed.