I dont have said:
I have an old Sony Vaio PCG-491L and its battery is gone. I would like to change to outlet power but I dont know where it is. Some help would be appreciate.Txs my e-mail is: email@example.com
I think you need to rephrase your question because I really don't understand what you wrote.
I am going to assume you want to simply use the laptop while plugged into the wall.
If so then all you need to do is to connect the laptop's AC power adapter / charger to the AC outlet. If you do not have the power adapter / charger, then you need to buy one.http://www.amazon.com/gp/product/B003U8GHQ0/ref=pd_lpo_k2_dp_sr_3?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B002DSA7W8&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0FBTF22HT94NGVCY1J47