Need Help With GameSave Willing to Pay (PayPal)

I am trying to mod Avatar Adventures Online. Yes I know you can mod the Credits/money, rank and the amount of Items. What I am trying to do is mod the Proficiency Points. Every time I try to mod my Proficiency Points the whole gamesaves resets, back to level 1.

I have met someone about 6 months ago and he was able to mod this. He told me I had to figure out the Checksum within the gamesave.
My question is how do you bypass the checksum or how to calculate the checksums?
I would like to learn how to do this NOT just doing it for me.
Thanks for your time.

My Game Save Download: http://www.mediafire.com/download/clxzemkkae4jcj0/SuperJumps117.xml

This Part of the gamesave code I believe is the checksum:
<IBN5100FileArray>
<int>8877</int>
<int>6989</int>
<int>6294</int>
<int>4357</int>
</IBN5100FileArray>

</tutorialLessonDisplayed>
<proficiencyCredits>0</proficiencyCredits>
<proficiencyTotalBP>10035</proficiencyTotalBP>
<proficiencyHPBoostUpgrades>65</proficiencyHPBoostUpgrades>
<proficiencyAPBoostUpgrades>65</proficiencyAPBoostUpgrades>
<proficiencyHealingUpgrades>0</proficiencyHealingUpgrades>
<proficiencyMovementSpeedUpgrades>20</proficiencyMovementSpeedUpgrades>
<proficiencyItemSpeedUpgrades>2</proficiencyItemSpeedUpgrades>
<proficiencyItemStrengthUpgrades>0</proficiencyItemStrengthUpgrades>
<proficiencyEnhanceDurationUpgrades>20</proficiencyEnhanceDurationUpgrades>
<proficiencyEnfeebleResistUpgrades>20</proficiencyEnfeebleResistUpgrades>
<proficiencyMoneyDropUpgrades>18</proficiencyMoneyDropUpgrades>
<proficiencyItemDropUpgrades>3</proficiencyItemDropUpgrades>
<WorldLineDivergenceMeter>0.077953</WorldLineDivergenceMeter>
<IBN5100FileArray>
<int>8877</int>
<int>6989</int>
<int>6294</int>
<int>4357</int>
</IBN5100FileArray>
<trialsPreviouslyCompleted>

Willing to Pay $20.00 (PayPal) to teach me how to bypass this.