Adding storage to a MacBook Pro

Since diving into the world of hi res digital downloads, I have used my MacBook Pro, circa 2015, to store my music. Getting very low on storage space. For folks that have encountered the same issue, what did you do to add extra storage space? Cloud? External drive, either disc or solid state? And someone mentioned that there are those that do surgery on MacBook pros and install larger internal hard drives. Thinking of going at least 1 TB. I want to make things as easy as possible. Preconfigured for Mac would be super. Thanks in advance for the suggestions.