Changing pads & disc's is generally very easy. Do one side at a time then you can check the other side if you get a bit stuck. When you remove the disc's be sure to clean the hub with emery cloth until it is back to shiny metal, also use brake cleaner to clean the disc of preservative, also when you come to push the pistons back into the caliper be careful that the fluid does not overfill the resevior ( makes a very good paint stripper). Make sure the pads are free in the caliper. When you have done both side I suggest that you bleed the calipers to get rid of the old fluid ( brake fluid is hygroscopic ( it absorbs water)). Before driving make sure the brake pedal feels firm with very little travel, then drive slowly and check the brakes stop you without any pulling etc. Do not brake from high speed until the brakes are bedded in.
TIP do not buy cheap pads and disc's no matter what your friendly motorist tells you, use a good motor factors even then they sell rubbish. another tip don't use H......ds they are far too expensive.
best of luck< I hope this helps.