You can't - since your callers are scammers, they don't care about breaking the law.  If your phone has a "number block" feature, you can use that to block their numbers.  If not, you may be able to assign a "no ring" tone, so that you don't have to deal with the phone constantly ringing.  Other than that, you may want to look at buying a call blocker - Google "call blockers" - you can get a good one for $60 or less.

Just received a call.from this number..claiming to be the irs. He proceed to tell me that I a criminal lawsuit filed against me..and proceeds to tell me that the local pd will be at my door at 9am how do I stop these calls

The voicemail said they were calling from the irs said I owe taxes and need to contact them immediately . The fact is I don't owe a dime . Anyway the voice was male , West Indian sounding . I am keeping the VM on file and forward it to the authorities .

Report the calls to the rel IRS here:

IRS:   http://www.irs.gov/

http://www.irs.gov/uac/Report-Phishing
phishing@irs.gov
http://www.treasury.gov/tigta/

http://www.irs.gov/uac/Tax-Scams-Consumer-Alerts
http://800notes.com/forum/ta-8c2f64bf2b91fa5/irs-warns-of-telephone-scam

?If you owe federal taxes, or think you might owe taxes, hang up and call the IRS at 800-829-1040. IRS workers can help you with your payment questions.
?If you don?t owe taxes, call and report the incident to the Treasury Inspector General for Tax Administration at 800-366-4484.
?You can also file a complaint with the Federal Trade Commission at FTC.gov. Add "IRS Telephone Scam" to the comments in your complaint.

For me, the message was from "David Ashely" who claimed to be an "IRS revenue officer" and he told me that a claim had been filed against me, and that I needed to call him back with my "criminal defense attorney information" before I was arrested by the county sheriff.  It was a little unnerving, but the guy's extraordinarily strong accent (so bad that I had to listen to the message several times to actually understand him) and the fact that I'm fairly confident that the IRS would have reached out in a more professional manner had there been an actual issue, made it very easy to just ignore this obvious scammer....

Good for you. A local TV station managed to get some info on the people threatening others with the scare. The call appeared to be based out of Toledo, OH but calling back gave no results. The story here:
http://woodtv.com/2014/03/28/couple-plays-irs-scam-call-to-target-8/

Alan Cooper supposedly from IRS called 3 times today and threatened me of police arrest tomorrow 12 pm and 9 years in jail as he claims that I had a tax deficiency of $2400.  I could immediately smell a foul play.