Quashing of fir in 379

Dear Experts, 

I request you to please offer your assistance. 

Incident: 

My Friend in an Alcoholic state boarded a train; he was badly under the influence of alcohol and some pills and was in no condition to judge where he was going. Till date he has no clue what he did and he doesn’t remember anything.

 There was a theft on the train.A bag of the lady was picked up and she complained to the GRP about the same. GRP caught my friend and recovered the belongings from him and booked him for this offence.

 He was brought to the police station and an FIR was lodged for theft. The party came and recognised the belongings.

Now my friend is formally arrested FIR registered and he is currently in jail for 14 days , also his bail plea was rejected.

 Now, in the mean time we contacted the complainant party and they are ready to pardon us and they don’t want to pursue further litigations. 

Is it possible to get the FIR quashed? What is the procedure for quashing? My friend has a very clean record and does not remember anything about the theft since he was drunk but as per the police things were recovered from him

Our Advocate said the powers are with the GRP SP and he can direct the court and this has to be done before my friend gets bail. If bail is granted the case will resume and we will have to pursue the case. PLS HELP