I used LiftOver to lift the Genome Position from hg18 to hg19. In order to convert the rs number, I looked at the following tutorial, and used their available python script (which uses Use RsMergeArch and SNPHistory). This produced a list of new snps, some lifted, unlifted or just unchanged. However it is not clear to me how I should proceed at this point, and/or this list is then used together with the data file b132_SNPChrPosOnRef_37_1.bcp.gz (a data file containing each dbSNP and its positions in NCBI build 37) to adjust the .map and .ped files accordingly (as stated in the method 2 of the above cited tutorial).
Any suggestions would be highly appreciated!