Hi,
Here is a link to the service manual for your tablet.
https://download.lenovo.com/consumer/mobiles_pub/lenovo_s8-50_hmm_en_20140828.pdf
It shows how to dis-assemble the tablet.
On p.37 there is list of the part numbers for the components. If you search online for this number 5D69A6N2YU (do not add Lenovo or any thing else to the search term), which is the part number for the LCD unit, you will get suppliers of the part. It isn't cheap.