Need procedure for changing oil on stratoliner

The proper instructions are on pages 6-10 thru 6-12 of the owners manaul. If you don not have a copy you can view one here.
https://www.starmotorcycles.com/star/service/viewmanual.aspx?ls=star&yr=2006&lid=2&mid=1191

Here is a list of oil filters which will fit the 'liners, besides the OEM filter:
This info was on the forum some time back, filters for Liners:

• Amsoil ……………………… (SMF103) chrome (SMF103C)
• Bosch ……………………… (3300) (3330) (3323)
• Mobil One…………………… M108
• BOSCH……………………….3300 3323
• K&N…………………………….KN-303
• NAPA GOLD……………...1358
• PUROLATOR……………….ML16817
• Purolator PureONE.....PL14612 Buy @ Amazon.com 2/$5.88
• Purolator PureOne......PL14610 Buy @ Amazon.com 2/$5.88

The 14612 is the short filter. The longer one, which also fits the Liner, is the 14610 model (in case it matters).

• STP…………………………...SDF13
• WIX…………………………..51358
• FRAM………………………...6017A
• HASTINGS…………………LF-113
• HI FLO………………………HF-303
• EMGO……………………….10-82220
• PER-FORM…………………J-503
• Super Tech………………..ST7317 (Wal-Mart)

The Wal-Mart ST 6607 is a little smaller than the stock filter and the 7317 is maybe a half inch longer. Both will work fine.

You will want to change the crush washers on the plugs.
The crush washers can be obtained at your nearest Yamaha dealer, or similar washers can be obtained at Advanced Auto. The size is 1/2 (or M14) called oversize, crush washers.
Oil-tite part #65310
They come in a 3 pack.