Tokoton~suru
zubon haitte
Say "tadaima" (I'm home), take off shoes, wash hands.
Take.
He gets pants off
"Kore o totte [kudasai]." 'Please take this.'
'Unko shitai.'
tsubone shta....i believe is literally underpants. i could be wrong. I'm sure there's a slang for boxers or underwear but this is all i can think of that's close.
You may say 'ki o tsukete (kudasai/ne).'
I take it it's a name, in which case ルピタ /ru pi ta/ would be its Japanese form.
You may say 'hitotsu wo toru.'
mew mu nachi go
you could say burned your pants or your pants wereburnt. Either one works