I can't find a Husqvarna Viking H Class 500 R. There is a 500E. Make sure that the presser foot is up and the needle is in the highest position. Use the hand wheel to move the needle by turning the wheel towards you. All machines follow a move from right to left, down, up, down threading pattern. Place the spool on the appropriate spool pin and put on the spool pin cap. First guide the thread around the thread guide to the left of the spool pin and then pull it down along the groove. Continue running the thread down the groove and then around the inside of the tab at the bottom. Bring the thread up to the thread take-up lever. Pass the thread through the thread take-up lever from right to left. Insert the thread in the left-most groove and bring it down to the thread guide. Guide the thread into the thread guide above the needle. To use the needle threader, lower the presser foot. Otherwise, push the thread through the eye of the needle from front to back. See the manual if you are using a vertical spool or a double needle. The needle threader can't be used with a size 60 needle or the multi-needle options.
For inserting the filled bobbin, raise the needle. Open the bobbin cover plate by pressing the release button to the right while pushing the left corner of the plate. Place the bobbin on the pin of the bobbin case with the bobbin rotating counter-clockwise when the thread is pulled gently. Pull the thread through the slot slightly to the left of the 6 o'clock position (12 hour clock) and then to the left. Gently hold the bobbin with a finger and pull the thread the second slot (near 8 o'clock). Pull out about 6" of thread heading towards the rear of the machine and replace the bobbin cover plate.
The manual for the H-Class 500E is available here:
https://www.husqvarnaviking.com/en-US/Machines/H-CLASS-500E . The current link to the manual is
https://www.husqvarnaviking.com/getattachment/Machines/H-CLASS-500E/HClass_500E_manual_EN_B.pdf.aspx . See page 11 (page 13 of the PDF) for threading the top thread. Page 15 (page 17 of the PDF) has the section on inserting the bobbin.
I hope this helps.
Cindy Wells