Garmin eTrex

[hud]

So
A donkey's age ago I bought an eTrex 10. I decided to dig it out the other day to use it and keep it as part of my ruckie. I am not interested in geocaching; I simply want it in the doomsday scenario where I get a bit lost to confirm a grid ref to get me back onto where I am meant to be and figure out where I am on my map. Does anyone have any idea how the flip I set the darn thing up to get this??? I've gone through the manual and am none the wiser!
Is there a setting compatible to OSNI grid refs?
Hud

[hud]

Think we have it sussed

Any tips still welcome tho

[DrMonkFish]

http://static.garmincdn.com/pumac/eTrex_10-20-30_OM_EN.pdf

http://static.garmincdn.com/pumac/etrex_10_QSM_EN.pdf

[Daithi2004]

Go to "Settings/Setup" then "Position Format" and scroll down until Irish Grid if you are in Northern Ireland and Republic of Ireland or British Grid if you are in England, Scotland and Wales