Step 1: Leave Santiago Chile.  We started in Chile, we were in Valparaiso, then spent the night in Santiago, woke up around 5 or 6 am and drove Northeast toward the Chile/Argentina border.  Traffic in Valparaiso especially and around Santiago was terrible the day before, but now that it was early in the morning, and a weekend, it was much better.  This drive will take roughly 3 hours, there are tolls and it crosses a country border.

Step 2: Pay some tolls.  I think there is only one, but the day before, driving to Valparaiso we hit a bunch of tolls.  They only accept Chile-cash, no cards.  We accidentally drove through a couple because I'm terrible at Spanish and we drove through the wrong lanes... I have yet to receive a ticket from the rental-car company.  The tolls are like 2-5 USD equivalent.

Step 3: Cross the border.  The border was very confusing for us.  We drove around a building on a gravel road, and the guy told us to keep going, you don't need to stop or do anything on your way out of Chile.  (You do need to do a lot on your way back into Chile, get your car searched, drug-dogged and documents/passport-checked).  The process of coming back did not go smoothly at all.  We had no documentation that we were ever in Argentina, and the guards were all very confused.  You need to tell them that you came from Chile and you only went to hike Aconcagua and then came back.  Apparently the Argentina immigration center is a few miles after Aconcagua, so if you proceed no further than Aconcagua, you are apparently in Chile/Argentinian Purgatory.

Step 4: Park your car, get a Hiking Permit. You're going to enter the National Park of Aconcagua, called: "Parque Provincial Aconcagua" on Google Maps.  Right off the road as you pull-in, you'll see the check-in building/ranger workstation.  Inside this building is where you buy a permit from a person working at a desk.  The permits are cheap, only like 13-25 USD-equivalent depending on what type you get.  (They only accept Argentinian Money) (We fully planned on getting Argentina-money but during our confusion at the border, we completely forgot.)  DO NOT FORGET YOUR ARGENTINA-MONEY.  We wasted two, precious hours trying to find someone to exchange some Chile-money.  Finally found a guy down the road who worked at a restaurant to traded us for a small fee.  Technically the hiking permit you get should be the one to Confluencia, aka Aconcagua base camp.  More confusion on our end, we didn't know where we were going and I have no idea what permit we actually got.  After you get your permit, drive a mile North, through a little gate thing, and park at the parking-lot up there, not down by the permit building.

Step 5: Start your hike to Aconcagua Base Camp.  You will be hiking North the entire time, then slightly Northwest.  You can turn around whenever you want, or just keep hiking North until you find yourself at the top of the tallest mountain in South America, one of the 7-Summits.  Base camp is called Confluencia with an elevation of 11,800 feet.  The hike is not too strenuous unless you carry a bunch of camera, lenses, drone-gear and water like i did.  Right off the bat, from the parking-lot i ran back to the car (forgot my hat) and was out of breath because of the elevation, it is noticeably different than sea-level, which we were at in Valparaiso the day before.

Step 6: Finish your hike to Aconcagua Base Camp.  The national park actually closes, unlike the ones in America, so be aware of what time you're supposed to return from your hike or the rangers might be mad at you.