You should be able to create a 2gb partition on the card and format that. The phone probably doesn’t care how big the card is*, only how large the filesystem is. So using a computer and card reader, delete the existing partition on the card, and then create a new partition at 2gb, and (optionally) a second partition with the remaining 6gb. Then format the partitions as FAT or FAT32 file systems.
How exactly you partition and format the card will depend on your operating system, and can probably be answered with a Google search.
Or, try the 8gb card as is, and see what happens.
*Sometimes memory cards will change key technology as they get larger, and some older devices will not be able to access larger cards.
I believe I used partition magic on such a card way back, but that might have been a USB drive.
Also
I did have a camera that had a 2 GB card limit in print, but a 8 GB card worked fine.
It’s surprising how many products designed for one memory standard turn out to be incompatible with later extensions (or fulfillment) or the standard. I’ve seen many problems with devices released when (say) 2GB chips were the standard and larger ones were only in prototype, which turn out to be incompatible with the later iterations even though everything was technically made to meet the standard.
On the flipside, there are also plenty of products that work just fine with things out of spec for what they claim to support. Generally, someone makes the decision that limiting official support to a smaller subset wouldn’t hurt sales enough to justify the extra money and effort to test with other configurations.
Sure; say, Nikon will only guarantee operation with specific models of 16GB SD card, when in reality any compliant card from any maker will likely work.
What I meant is that while a camera or phone designed early in a memory standard is supposed to be able to work with standard extensions under development, the reality a year down the road is that they won’t. The camera says it is THX-1138 compliant, but the larger chips under that standard just don’t work in it because the standard evolved or the camera maker cut corners.