Turn blocks into block displays either by breaking or commands
Block To Display is clientside mod that allows turning blocks into block displays.
Change your gamemode to Creative, use command /blocktodisplay toggle and start breaking blocks, after you have broken block, your client will send /summon -command to server which summons the block display. You are required to have permission to use /summon -command. When you are done, remember to toggle this off with the same command.
You can also use command /blocktodisplay replacenear <block> <radius> to replace specific blocks on given radius. You are required to have permission to use /summon and /setblock -commands.
/blocktodisplay replace <from> <to> command