[TG11] Axiom Pro Base Chart

Have new Axiom Pro works super have most recent update on all.
Q. It seems my unit was preloaded with base Navionics. How could I delete base Navionics an make my unit neutral for C-map and Navionics etc.-
Please advise --Make my Axiom Pro clean from preinstalled base chart.
Yes I prefer CMAP EN 299.48.
Best Regards
Lars