I think the cluster does have to be removed to access the bulbs, so the tach has to come out, so radio or steering wheel too, etc. If cluster removed maybe replace all bulbs with LED so it puts off doing it again.
That said, note from tech manual:
“ The low fuel warning lamp fitment appears too small to accommodate (currently available) BA9s base red LED.
Since this is a (presumably) very occasionally lit bulb it can expect to have a long life even as an incandescent and can be replaced by and original style incandescent. “
If you do find an LED that fits, maybe update tech manual.
Are you sure the low fuel bulb is gone? Have you checked the feed circuit if you think it not lighting? Probably easier to check that before you pull out the cluster.