Yes, the HDD can be replaced in the ASUS X543MA-GQ1015T Laptop
Based on the dimensions of the Asus X543MA-GQ1015T Laptop, which are 381 x 251 x 27.2 mm (width x height x depth), it's reasonable to estimate that the dimensions of the hard disk would fall within the range of standard laptop hard drive sizes. Common dimensions for a 1TB laptop hard drive are approximately 2.5 inches wide, 0.3 inches high, and 3.9 inches deep.