diff --git a/tests/letstest/README.md b/tests/letstest/README.md
index a9b4db6b5..0155065b0 100644
--- a/tests/letstest/README.md
+++ b/tests/letstest/README.md
@@ -1,5 +1,5 @@
 # letstest
-simple aws testfarm scripts for certbot client testing
+Simple AWS testfarm scripts for certbot client testing
 
 - Configures (canned) boulder server
 - Launches EC2 instances with a given list of AMIs for different distros
@@ -15,30 +15,59 @@ simple aws testfarm scripts for certbot client testing
     are needed, they need to be requested via online webform.
 
 ## Usage
+  - To install the necessary dependencies on Ubuntu 16.04, run:
+```
+sudo apt install awscli python-yaml python-boto3 fabric
+```
+
   - Requires AWS IAM secrets to be set up with aws cli
   - Requires an AWS associated keyfile <keyname>.pem
 
 ```
->aws configure --profile HappyHacker
+>aws configure --profile <profile name>
 [interactive: enter secrets for IAM role]
->aws ec2 create-key-pair --profile HappyHacker --key-name MyKeyPair --query 'KeyMaterial' --output text > MyKeyPair.pem
+>aws ec2 create-key-pair --profile <profile name> --key-name <key name> --query 'KeyMaterial' --output text > whatever/path/you/want.pem
 ```
+Note: whatever you pick for `<key name>` will be shown to other users with AWS access.
+
+When prompted for a default region name, enter: `us-east-1`
+
 then:
 ```
->python multitester.py targets.yaml MyKeyPair.pem HappyHacker scripts/test_apache2.sh
+>python multitester.py targets.yaml /path/to/your/key.pem <profile name> scripts/<test to run>
 ```
 
+You can only run up to two tests at once. The following error is often indicative of there being too many AWS instances running on our account:
+```
+NameError: name 'instances' is not defined
+```
+
+If you see this, you can run the following command to shut down all running instances:
+```
+aws ec2 terminate-instances --profile <profile name> --instance-ids $(aws ec2 describe-instances --profile <profile name> | grep <key name> | cut -f8)
+```
+
+It will take a minute for these instances to shut down and become available again. Running this will invalidate any in progress tests.
+
+A folder named `letest-<timestamp>` is also created with a log file from each instance of the test and a file named "results" containing the output above.
+The tests take quite a while to run.
+
+Also, the way all of the tests work is to check if there is already a boulder server running and if not start one. The boulder server is left running between tests,
+and there are known issues if two instances of boulder attempt to be started. After starting your first test, wait until you see "Found existing boulder server:" or if you see output
+about creating a boulder server, wait a minute before starting the 2nd test. You only have to do this after starting your first session of tests or after running
+the `aws ec2 terminate-instances` command above.
+
 ## Scripts
-example scripts are in the 'scripts' directory, these are just bash scripts that have a few parameters passed
+Example scripts are in the 'scripts' directory, these are just bash scripts that have a few parameters passed
 to them at runtime via environment variables.  test_apache2.sh is a useful reference.
 
 Note that the <pre>test_letsencrypt_auto_*</pre> scripts pull code from PyPI using the letsencrypt-auto script,
 __not__ the local python code.  test_apache2 runs the dev venv and does local tests.
 
-see:
+See:
 - https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-started.html
 - https://docs.aws.amazon.com/cli/latest/userguide/cli-ec2-keypairs.html
 
-main repos:
+Main repos:
 - https://github.com/letsencrypt/boulder
 - https://github.com/letsencrypt/letsencrypt