Hi @vardhanyash
Here's the [http://h10032.www1.hp.com/ctg/Manual/c02834221.pdf|maintenance and service guide] for the G6 model series
Go to p.46 to view the procedure to remove the HDD so that it can be replaced with an SSD. The laptop supports ''2.5" sata 6Gb/s'' SSDs having a capacity of up to 4TB (4000GB)
Go to p.52 to view the procedure to remove/replace the memory modules. The laptop supports 8GB of PC3 10600 1333 MHz memory in 2 slots i.e. 2 x 4GB memory modules