Ahh so you want to do a partical history deletion. Well theres no single general procedure that attacks all cases. But the easiest one is cutting all history of at a certain point.
Delete the input connection at the point you want to kill your history. (yes that means to delete teh arrow not the node)
create a empty shape node inject the connection to the shpe nodes input, connect shape nodes output to where the connection use to point. Then delete the connection into the newly created shape node (note dont delete the Node again just connection, thisway maya will cache whetever shape you have at this point). Your now free to delete the preceding history.
Theres a significant amount of variations to this tough, it all depends of the ordder of you network and theres literally millions of variations to the theme depending on the exact configuration, some which are impossible also. For example the shape node is not neccesery if the belndshape has all blens baked in, as just change to base input may be enough.