Mash as normal. Bring it to a boil, add yeast nutrient and irish moss. Do not add hops. Hops will prevent your beer from souring. Boil for 10 minutes to add the nutrients/moss and to kill any nasties. Cool wort to 100 degrees Fahrenheit. Transfer warm wort to carboy. Follow sanitation procedures very carefully...you don't want nasties in your sour wort.

Add roughly 1 tbsp of 88% lactic acid solution to pre-acidiy wort to a PH between 4.0 and 4.4. After adding Lactic Acid, add 1 Lemon Ginger (taste doesn't matter but this is the most appropriate for a gose) Goodbelly Super Shot (available at Sprouts and some specialty grocers and health stores).

http://goodbelly.com/super-shot/

This has 50 billion units of Lactobacillus Plantarum. Seal the fermenter up with an airlock (waterless is best if you have it since the dropping temp can cause it to suck the liquid back into the fermenter). Use alcohol in a normal 3 piece airlock.

If you have a temp controller and heating pad, tape the probe to the carboy, bubble wrap over top of it to insulate it, and then tape the heat wrap onto the fermenter (making sure not to go over top of the probe/wrap). set your temp controller to 85 or 90 degrees and let it sit for a day and a half to two days. If you do not have a heat wrap/temp controller let it sit in the warmest part of your house and it will free fall to room temp...let it sit for 2 days. After the two days you will want to rehydrate 2 packets of US-05 and pitch them, aerating or shaking is fine. Let ferment at 64 degrees for 2 days and begin to bump up temp by 1 degree each day until you get to 70 degrees or so. Make sure fermentation is finished then let sit on yeast for a couple days to clean up. Typically about 2-3 weeks for fermentation/rest before bottling.