Hyundai Repair: Clutch problems?, clutch fluid, clutch problems

Question
QUESTION: Hello,

My car has been parked for about a month while I was away on vacation.When I got into drive it today,it was extremely hard to get it into first gear, and subsequently to change gears while driving. When it is in each gear the car runs fine i.e. clutch not slipping. To get it to go into reverse,  it grinds the whole way ( doesn't seem like the clutch is engaged at all!). I have checked the clutch fluid level and it is fine. Is it possible I need a new clutch? How does that happen if I haven't been driving it?

Thank you for your help!

ANSWER: Hello Andrea,
I do not think you will need a new clutch. Make sure your clutch sleeve is working by asking somebody to press the clutch pedal while monitoring the lever on the tranmission . It should be working back and forth. If it is working fine, then your trany oil is sluggish. Changing the trany oil and adding smooth shift additive might be your solution.

---------- FOLLOW-UP ----------

QUESTION: I have checked the clutch sleeve and it seems to be working fine. Where is the release spot / addition spot for the transmission oil? And is this something I can do myself, and if so is there an oil / and smooth shift additive you recommend?

Thank you again!
Thank you again !

Also, when my boyfriend was looking at it last night, he said the clutch was slipping slightly in the higher gears ( 4th and 5th)... does this change the diagnosis at all ?

Answer
Hello again,
You should focus on shifting problem right now. Draining the transmission oil is not that hard but filling it is tricky. Filling hole (also it is oil level checking hole) is located sideways on the front side of the transmission.You will need a 17 mm socket. Draining plug is under the transmission and you will need a 24 mm socket. Because of it's messy nature I recommend you to take your car to a dealer or lube station. For the additive, I do not want to give you any specific brand. Any additive will do . Make sure it is  for manual transmission. After transmission oil changed , let me know about the slipping problem so we can talk about it.