open the formula.xml file in the Matchserver folder.
What you'll see is somthing like
<FORMULA_TABLE id="GettingExpLM">
BLAHBLAHBLAH
</FORMULA_TABLE>
Change them to be somthing like
This would be 1x which would be slow exp gain. Experiment, but what ever you do leave the .1 or .2 after the numbers..dont go over 40x because its super fast and basically you level up to 80 in one game.
<FORMULA_TABLE id="GettingExpLM">
<LM lower="1" upper="20">1</LM>
<LM lower="21" upper="30">1</LM>
<LM lower="31" upper="40">1</LM>
<LM lower="41" upper="45">1.1</LM>
<LM lower="46" upper="50">1.1</LM>
<LM lower="51" upper="55">1.1</LM>
<LM lower="56" upper="60">1.1</LM>
<LM lower="61" upper="65">1.1</LM>
<LM lower="66" upper="70">1.1</LM>
<LM lower="71" upper="75">1.1</LM>
<LM lower="76" upper="80">1.1</LM>
<LM lower="81" upper="85">1.2</LM>
<LM lower="86" upper="90">1.2</LM>
<LM lower="91" upper="95">1.2</LM>
<LM lower="96" upper="99">1.2</LM>
</FORMULA_TABLE>