That would work if his guild had the T3 guild hall in Antonica. but reading his post, it looks like his guild has the T2 guild hall in South Qeynos. clicking on the bell in Antonica will do nothing to help him get to his guild hall.
anyway, to answer the OP, you can sneak in through the sewers (not that difficult), buy a "Magic Door to the Guild Hall" (or whatever it is called), or use someone else's magic door. but the first time you make the trek, your guild should have the Guild Teleportation Beacon (they purposefully reduced the cost so that all guilds could at least get that). click that and you will get your Recall to Guild Hall spell so you just have to call back like you were returning home (only a much faster cool down timer - 15 minutes for Guild hall recall as opposed to the 60 minute city recall timer).
So there are your options. hope that helps.