Experian Score vs. Fico Score

There really is no linear "point for point" comparison. FICO is a proprietary algorithm that Fair Isaac keeps very secret, for a lot of obvious reasons. As such, while a lot of us can tell you what can help raise / lower your score, and can even make educated guesses as to how substantial those changes will be ("a lot" or "not much"), none of us can really tell you what a specific action will do -- let alone how to correlate actions on an Experian score to your FICO score.

That being said, there's a lot of good (and bad) general advice out there to help you improve your score:

1) Review your report for inaccurate or outdated information. If you find any, have it corrected or deleted.
2) Look for any entries that might be PFD-friendly. While no CA is ever obligated to do a PFD, some will, and it rarely hurts to ask. Your odds of pulling this off on old debts are better than on new ones.
3) For any current accounts with a poor payment history, consider a goodwill letter. This can help if, for example, you were seriously delinquent two years ago but have made on-time payments ever since.
4) If the negative entry is still with the OC, talk to the OC. A number of OCs would rather modify your payment (such as by recapitalizing interest) than send the account out for collections. Note that depending on the numbers and your future plans, these options can sometimes be very expensive in the long run.
5) Start paying. There are varying schools of thought on this, but IMHO, a paid debt is always better than an unpaid one -- though only barely. Be careful in making payments -- if you make a partial payment on an old debt, you run the risk of restarting the SOL.

Finally, never, ever, under any circumstances, talk to a debt collector over the phone. Always communicate in writing via CRMM.

The suggestions above are very general and don't necessarily apply to everyone. If you can post some more specifics, we might be able to offer some better help.

Good luck!