You insulted him! Fine, I'll give you specific directions.
Step 1: Go here. Help
Step 2: Stay there.
Help is for Blockland related questions only.
Right, there's a way to do it but it requires a few additional steps.
1:
http://www.online-image-editor.com/2: Upload your image
3: Crop the image in half (37-38 pixels if you're going 75x75)
4: Mirror the cropped image
5: Save the half and re-upload the original file
6: Go to the Wizards catagory and use Overlay Image
7: Line that stuff up and apply it
8: Save the mirrored GIF
There's probably an easier way but this one can be done completely online and free.
God people need to be spoon fed instructions don't they.
Also I don't want to be a mudflap.