Need to delete backed up Time Machine files on a new Macbook

Bit of a weird one here so would appreciate the help.

I’m having a common problem of not being able to delete Time Machine back up files on an external hard drive and getting the ‘the operation can't be completed because backup items can't be modified’. I’ve seen a lot of support which suggests using Time Machine itself to delete files, but the problem is I’m not on the same Macbook as I was when I backed up.

I have three different Time Machine back ups from my old Macbook on an external hard drive, as well as an additional one back up from my current Macbook, and only this final backup is recognised in Time Machine. Using the old Macbook is not an option, so essential I now have three different versions of my previous data backed up.

I’d really like to be able to delete some of this data as there are a lot of duplicates between the three back ups. I feel I could free up at least 300gb if I could delete these back up files. If anyone has a solution that does not involve buying a new external harddrive I’d really appreciate it.

 

Fantastic thank you - already freed up a good 100gb! Thanks for the help