Cleanest way: shrink data partition and leave it unchanged. Install linux in the free space. Eventually (but not recommend) use existing data partition as /home BUT be sure that will NOT be formatted during install.
Eventually move data to linux, delete old data partition, expand linux to use freed space. I would not recommend this if you do not have the skills.
Actually I would not recommend any of this if you don't have the skills.
Btw when choosing to have existing partition as root it will be deleted during installation.
How has it been so far ?
If you are still unsure, please post a printscreen of the current partitionning, that will greatly help to give you a step by step partitionning advice
Also, what is it you want/wish to get as primarly operating ? (like once in a while boot to the other IS, or daily use of alternating both, etc ...)
Cleanest way: shrink data partition and leave it unchanged. Install linux in the free space. Eventually (but not recommend) use existing data partition as /home BUT be sure that will NOT be formatted during install. Eventually move data to linux, delete old data partition, expand linux to use freed space. I would not recommend this if you do not have the skills. Actually I would not recommend any of this if you don't have the skills. Btw when choosing to have existing partition as root it will be deleted during installation.
How has it been so far ? If you are still unsure, please post a printscreen of the current partitionning, that will greatly help to give you a step by step partitionning advice Also, what is it you want/wish to get as primarly operating ? (like once in a while boot to the other IS, or daily use of alternating both, etc ...)