It is possible to do this in Terminal, but the operation is not without risks. I
strongly recommend doing a backup of your “MacIntosh” partition on that second disk before doing this (and of course any other data you want to save on that disk). Normally, Boot Camp should be able to remove its partition for you. However, given that it is apparently not able to, it could mean that a disk erase is inevitable. Use “diskutil list” once more before typing the command below, just to make sure that the disk identifiers are still the same. If you enter the wrong identifiers, you could delete the wrong partitions.
To explain this command. “diskutil mergepartitions” takes four parameters: format, name, starting partition, ending partition. It will keep the starting partition (in your case “MacIntosh” disk
1s2) and will remove everything after it up to and including the ending partition (so disk
1s3 and disk
1s4). Afterwards it will attempt to resize the starting partition to regain the space. If the resizing is not possible for some reason, then it will ask you whether you want to erase the first partition as well. You can respond with “y” or “n”. If you respond with “y” then it will reformat that starting partition into the chosen format and name, it will cancel if you choose “n”. So be sure to read the output.
You can type just “diskutil mergepartitions” in Terminal to get more information about this.
Code:
sudo diskutil mergepartitions JHFS+ MacIntosh disk1s2 disk1s4