You need to break the seal off in order to get the new oil inside, unless
you have Mike's insulin syringe handy! After that, the seal is broken and
excess lubricant will be expelled from the edge of the blades at 3000rpm!
Oil will not fry the card, and gravity causes leaking oil to
be slung into the hub cavity instead of the outside blade
area, where that drop or two of oil will not be enough go
anywhere else.
If carefully peeling the sticker back doesn't preserve
ehough of the adhesive to seal again, just take the whole
sticker off and put another one on, perferribly with an
adhesive that is resistant to oil. If you had a rare card
which kept the fan upside down so the oil was prone to run
out, all the more reason to use a thicker oil more reistant
to running, and to leave the card sitting with sticker off
for awhile to see if there is any excess that leaks out (and
can be wiped off thoroughly before putting sticker back on.
It depends on how worn the fan, how long this relube will
last in addition to the (higher) viscosity of the lube
chosen.