Your amino acid esters should be solubilized in an organic solvent, may be diethyl ether, and then you may insufflate gaseus HCl into this solution. Gaseus HCl may be easily produced by adding, dropwise, conc. H2SO4 to NaCl. The Developed gas (HCl) may be bubbled into the organic solution by the use of a glass tube. The formation of hydrochloride products is immediate and they will separate from the soultion as a precipitate which may be recovered by filtration. A wash of the solids with the used organic solvent may be of help in eliminating the remaining traces of unreacted amino acid esters.

You may prepare the necessary apparatus by the use of a two neck flask, a dropping funnel in the upper neck and a glass connector (tube) in the second neck with one of the ends immersed in the organic solution. The Conc. acid should be poured in the dropping funnel and the NaCl in the two neck flask.

Be sure to work using all the available individual protection and under a hood.

Dear Alessandro Venditti,

It was a grate pleasure in receiving reply from you....

Thank you for your help...i think for sure i will get my product.

I will be back after the reaction......

Prepare a concentrated solution of the amino acid, add HCl to lower the pH, and add organic solvent to induce precipitation

Dear Dr Manneganti you're welcome. 

The procedure suggested by Dr Gonzalez may be appliable on large amount of starting materials. To improve the yield of the reaction is better to use anhydrous solvents since hydrochlorides are water soluble compounds. 

Perhaps of some interest for your query ― considering the L-histidine / L-histidine hydrochloride case:

https://www.researchgate.net/post/I_have_L-histidine_hydrochloride_monohydrate_Help_me_please_how_can_I_eliminate_HCl_and_water_molecule_to_obtain_L-histidine_only