Any such person presently serving in any of said capacities may purchase prior service credit for the period of time he has so served by paying to the Police and Firemen's Retirement System of New Jersey an amount equal to the contributions he would have been required to have made had such service heretofore been deemed to be service as a member of the police or fire department. Application for such prior service credit shall be made to the retirement system within six months of the effective date of this amendatory act, P.L. 1992, c.73, and payment therefor may be in a lump sum or in installments as the commission may determine by rule or regulation.
N.J.S. § 43:16A-3.2