Kannan,

Here are the steps to make it easier for you.
1) First run the schedule (F9) to make sure that all date and logic are refreshed and correct.
2) Create a users define orig_Start Date, orig_Finish Date and orig_Duration field.
3) Run a global change to transfer the Star Date, Finish Date and Original Duration to created users define field as mention on step 2.
4) Modify the bar layout and add users define date on a bar layout (Gantt Charts) to show the users defined bar below the original bar. ( You may change the row height if necessary to fit the new bar)
5) Export Activity relationship into excel spreadsheet. (these will be used to change the lag duration if it has)
6) Run a global change to change remaining duration for all activities in progress (Criteria : where activity status equals in progress then remaining duration = remaining duration * 1.25)
7) Run a global change to change Original duration for all activities (Criteria : where activity type equals Task dependent then original duration = original duration * 1.25)
8) Open the exported activity relationship excel file and change the lag (lag * 1.25) and save
9) Import the modified excel activity relationship file with the new lag figures.
10) Then modify the existing calendar to reflect the new calendar hours per day then tick it as a default
11) Change the time unit under user preference to reflect the new calendar hour (i.e. : 10 Hours/day, 50 Hours/week, etc…)
12) Run the schedule (F9) then check if the user defined bars are the same as the original bar.
If the users define bar is the same as the original bar then you successfully fixed the calendar. Good Luck!!!

Now on your Resource change the default unit/time = 10/d and max unit/time to 10/d
Also check the resource assignment if unit also change. If not, you need to adjust them.

Note: user defined orig_Duration will contain hour or unit (i.e. 1 day = 8 hour)

Best Regards,
Rodel