The available battery guide warns that internal adhesive makes cell removal exceptionally difficult. The large display adds an opening step before reaching the battery.
What to check before buying
Battery path
iFixit's Tab S8 Ultra battery guide specifically warns that internal adhesive makes this repair extremely difficult. A battery quote should reflect that disassembly work rather than the price of a cell alone.
Scope of evidence
The linked procedure documents battery replacement; it does not by itself establish an easy route to other internal parts. Compare a concrete service quote for this exact Ultra model before assuming work is like a smaller Tab S8.