Birmingham has really good transport links to pretty much everywhere.
The best Postcode to use for navigation is B5 5SR, this will lead you to Floodgate Street Birmingham, just follow the signs when you get there.
Both Birmingham New Street and Birmingham Moor Street stations are within a 10 min walk to the event.
Birmingham Coach station is basically right next the venue (and incidentally its the closest cash point too). Any of the National Express Buses will take you right there from anywhere in the UK easy peasy. Mega Bus stops can be a little more random, so check with them where the stops are but they normally stop within a 15 min walk from the festival.
Head for B55SR Floodgate Street, and if you get lost ask for directions to The Custard Factory (every Brummie worth their salt will know where you mean!) If you are coming from the city centre, walk down Digbeth High Street until you get to The Kennedy Mosaic, then turn left and that will take you down FLoodgate Street and Boxxed is on your left jsut before the Railway arch.
If you’re driving to Swingamajig why don’t you add any potential spare seats you have on GoCarShare? They connect you with people looking for a ride who then contribute to your journey costs. It’s a great fun, green and cost effective way to travel to Swingamajig, so please add your journey and spare seat capacity and you’ll meet some interesting people too!