You cant its only minimum level requirement not max.
For example:
I can enter Minor with my Priest(115+9), Wiz(106), Ranger(99). Minimum level requirement is 90.
Inter only my Priest(115+9), Zerker(115), Scout(115+3) can enter. Minimum level requirement is 115.
Superior only Transcended(115+50) can enter. But considering how Inter is i believe this dung is impossible with current gear(+18 accs and such).
In my experience when i came back to check out the new elemental dungeon I got one of my rangers level 95 getting a little over 15% exp per stage and i was doing runs till stage 4 so that's a little bit higher than 60% per run. My wizard was level 102 and with the days I've been playing and some dung reset scrolls she got to 105 easy. My Priest was different cause i had to enter Inter dung to get good exp(0.2%) tho minor gives her more than i would ever get per killing mobs. Around 0.7% first 5 stages and 2% stages 6-9.
So far my recommendation for Minor dungeon is get a medium geared(Twins, ok-ish weapon, +5 Onyx) character to clean it up for you and don't waste your time with the last stage(5), the boss is not worth it.
For Inter a full pt with a Rumir, Def/Guard, Priest, other damage deals is a must with pro gear(Upgrades). The mobs hit with no mercy and you can barely scratch them with twins or even artisans/insurgents, upgrade boss drops is a must.
Get some friends to add you in any free slot available for this Dung. The exp is insane for 115+0 characters and you could get to +20 without too much effort.
GL