Before diving into the "how," we must address the "why." The SM-T285 features a Spreadtrum SC8830 chipset, 1.5GB of RAM, and 8GB of internal storage. Android versions beyond 7.1 (like Android 8-10) often struggle on these specifications. They require more RAM and CPU cycles for background processes.
Before starting, ensure you download these files to your computer or an external microSD card inserted into the tablet: Custom Recovery: Find a compatible version of TWRP (Team Win Recovery Project) specific to the The Custom ROM: Search the XDA Forums or trusted archives for the LineageOS 14.1 UNOFFICIAL zip file for (the SM-T285 codename). Google Apps (GApps): Download the Open GApps package. Choose Android 7.1
You can upgrade your Samsung Galaxy Tab A 7.0 (2016) SM-T285 Go to product viewer dialog for this item.